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llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/galois.py

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+r"""
+Construct transitive subgroups of symmetric groups, useful in Galois theory.
+
+Besides constructing instances of the :py:class:`~.PermutationGroup` class to
+represent the transitive subgroups of $S_n$ for small $n$, this module provides
+*names* for these groups.
+
+In some applications, it may be preferable to know the name of a group,
+rather than receive an instance of the :py:class:`~.PermutationGroup`
+class, and then have to do extra work to determine which group it is, by
+checking various properties.
+
+Names are instances of ``Enum`` classes defined in this module. With a name in
+hand, the name's ``get_perm_group`` method can then be used to retrieve a
+:py:class:`~.PermutationGroup`.
+
+The names used for groups in this module are taken from [1].
+
+References
+==========
+
+.. [1] Cohen, H. *A Course in Computational Algebraic Number Theory*.
+
+"""
+
+from collections import defaultdict
+from enum import Enum
+import itertools
+
+from sympy.combinatorics.named_groups import (
+    SymmetricGroup, AlternatingGroup, CyclicGroup, DihedralGroup,
+    set_symmetric_group_properties, set_alternating_group_properties,
+)
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.combinatorics.permutations import Permutation
+
+
+class S1TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S1.
+    """
+    S1 = "S1"
+
+    def get_perm_group(self):
+        return SymmetricGroup(1)
+
+
+class S2TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S2.
+    """
+    S2 = "S2"
+
+    def get_perm_group(self):
+        return SymmetricGroup(2)
+
+
+class S3TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S3.
+    """
+    A3 = "A3"
+    S3 = "S3"
+
+    def get_perm_group(self):
+        if self == S3TransitiveSubgroups.A3:
+            return AlternatingGroup(3)
+        elif self == S3TransitiveSubgroups.S3:
+            return SymmetricGroup(3)
+
+
+class S4TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S4.
+    """
+    C4 = "C4"
+    V = "V"
+    D4 = "D4"
+    A4 = "A4"
+    S4 = "S4"
+
+    def get_perm_group(self):
+        if self == S4TransitiveSubgroups.C4:
+            return CyclicGroup(4)
+        elif self == S4TransitiveSubgroups.V:
+            return four_group()
+        elif self == S4TransitiveSubgroups.D4:
+            return DihedralGroup(4)
+        elif self == S4TransitiveSubgroups.A4:
+            return AlternatingGroup(4)
+        elif self == S4TransitiveSubgroups.S4:
+            return SymmetricGroup(4)
+
+
+class S5TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S5.
+    """
+    C5 = "C5"
+    D5 = "D5"
+    M20 = "M20"
+    A5 = "A5"
+    S5 = "S5"
+
+    def get_perm_group(self):
+        if self == S5TransitiveSubgroups.C5:
+            return CyclicGroup(5)
+        elif self == S5TransitiveSubgroups.D5:
+            return DihedralGroup(5)
+        elif self == S5TransitiveSubgroups.M20:
+            return M20()
+        elif self == S5TransitiveSubgroups.A5:
+            return AlternatingGroup(5)
+        elif self == S5TransitiveSubgroups.S5:
+            return SymmetricGroup(5)
+
+
+class S6TransitiveSubgroups(Enum):
+    """
+    Names for the transitive subgroups of S6.
+    """
+    C6 = "C6"
+    S3 = "S3"
+    D6 = "D6"
+    A4 = "A4"
+    G18 = "G18"
+    A4xC2 = "A4 x C2"
+    S4m = "S4-"
+    S4p = "S4+"
+    G36m = "G36-"
+    G36p = "G36+"
+    S4xC2 = "S4 x C2"
+    PSL2F5 = "PSL2(F5)"
+    G72 = "G72"
+    PGL2F5 = "PGL2(F5)"
+    A6 = "A6"
+    S6 = "S6"
+
+    def get_perm_group(self):
+        if self == S6TransitiveSubgroups.C6:
+            return CyclicGroup(6)
+        elif self == S6TransitiveSubgroups.S3:
+            return S3_in_S6()
+        elif self == S6TransitiveSubgroups.D6:
+            return DihedralGroup(6)
+        elif self == S6TransitiveSubgroups.A4:
+            return A4_in_S6()
+        elif self == S6TransitiveSubgroups.G18:
+            return G18()
+        elif self == S6TransitiveSubgroups.A4xC2:
+            return A4xC2()
+        elif self == S6TransitiveSubgroups.S4m:
+            return S4m()
+        elif self == S6TransitiveSubgroups.S4p:
+            return S4p()
+        elif self == S6TransitiveSubgroups.G36m:
+            return G36m()
+        elif self == S6TransitiveSubgroups.G36p:
+            return G36p()
+        elif self == S6TransitiveSubgroups.S4xC2:
+            return S4xC2()
+        elif self == S6TransitiveSubgroups.PSL2F5:
+            return PSL2F5()
+        elif self == S6TransitiveSubgroups.G72:
+            return G72()
+        elif self == S6TransitiveSubgroups.PGL2F5:
+            return PGL2F5()
+        elif self == S6TransitiveSubgroups.A6:
+            return AlternatingGroup(6)
+        elif self == S6TransitiveSubgroups.S6:
+            return SymmetricGroup(6)
+
+
+def four_group():
+    """
+    Return a representation of the Klein four-group as a transitive subgroup
+    of S4.
+    """
+    return PermutationGroup(
+        Permutation(0, 1)(2, 3),
+        Permutation(0, 2)(1, 3)
+    )
+
+
+def M20():
+    """
+    Return a representation of the metacyclic group M20, a transitive subgroup
+    of S5 that is one of the possible Galois groups for polys of degree 5.
+
+    Notes
+    =====
+
+    See [1], Page 323.
+
+    """
+    G = PermutationGroup(Permutation(0, 1, 2, 3, 4), Permutation(1, 2, 4, 3))
+    G._degree = 5
+    G._order = 20
+    G._is_transitive = True
+    G._is_sym = False
+    G._is_alt = False
+    G._is_cyclic = False
+    G._is_dihedral = False
+    return G
+
+
+def S3_in_S6():
+    """
+    Return a representation of S3 as a transitive subgroup of S6.
+
+    Notes
+    =====
+
+    The representation is found by viewing the group as the symmetries of a
+    triangular prism.
+
+    """
+    G = PermutationGroup(Permutation(0, 1, 2)(3, 4, 5), Permutation(0, 3)(2, 4)(1, 5))
+    set_symmetric_group_properties(G, 3, 6)
+    return G
+
+
+def A4_in_S6():
+    """
+    Return a representation of A4 as a transitive subgroup of S6.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    G = PermutationGroup(Permutation(0, 4, 5)(1, 3, 2), Permutation(0, 1, 2)(3, 5, 4))
+    set_alternating_group_properties(G, 4, 6)
+    return G
+
+
+def S4m():
+    """
+    Return a representation of the S4- transitive subgroup of S6.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    G = PermutationGroup(Permutation(1, 4, 5, 3), Permutation(0, 4)(1, 5)(2, 3))
+    set_symmetric_group_properties(G, 4, 6)
+    return G
+
+
+def S4p():
+    """
+    Return a representation of the S4+ transitive subgroup of S6.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    G = PermutationGroup(Permutation(0, 2, 4, 1)(3, 5), Permutation(0, 3)(4, 5))
+    set_symmetric_group_properties(G, 4, 6)
+    return G
+
+
+def A4xC2():
+    """
+    Return a representation of the (A4 x C2) transitive subgroup of S6.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    return PermutationGroup(
+        Permutation(0, 4, 5)(1, 3, 2), Permutation(0, 1, 2)(3, 5, 4),
+        Permutation(5)(2, 4))
+
+
+def S4xC2():
+    """
+    Return a representation of the (S4 x C2) transitive subgroup of S6.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    return PermutationGroup(
+        Permutation(1, 4, 5, 3), Permutation(0, 4)(1, 5)(2, 3),
+        Permutation(1, 4)(3, 5))
+
+
+def G18():
+    """
+    Return a representation of the group G18, a transitive subgroup of S6
+    isomorphic to the semidirect product of C3^2 with C2.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    return PermutationGroup(
+        Permutation(5)(0, 1, 2), Permutation(3, 4, 5),
+        Permutation(0, 4)(1, 5)(2, 3))
+
+
+def G36m():
+    """
+    Return a representation of the group G36-, a transitive subgroup of S6
+    isomorphic to the semidirect product of C3^2 with C2^2.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    return PermutationGroup(
+        Permutation(5)(0, 1, 2), Permutation(3, 4, 5),
+        Permutation(1, 2)(3, 5), Permutation(0, 4)(1, 5)(2, 3))
+
+
+def G36p():
+    """
+    Return a representation of the group G36+, a transitive subgroup of S6
+    isomorphic to the semidirect product of C3^2 with C4.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    return PermutationGroup(
+        Permutation(5)(0, 1, 2), Permutation(3, 4, 5),
+        Permutation(0, 5, 2, 3)(1, 4))
+
+
+def G72():
+    """
+    Return a representation of the group G72, a transitive subgroup of S6
+    isomorphic to the semidirect product of C3^2 with D4.
+
+    Notes
+    =====
+
+    See [1], Page 325.
+
+    """
+    return PermutationGroup(
+        Permutation(5)(0, 1, 2),
+        Permutation(0, 4, 1, 3)(2, 5), Permutation(0, 3)(1, 4)(2, 5))
+
+
+def PSL2F5():
+    r"""
+    Return a representation of the group $PSL_2(\mathbb{F}_5)$, as a transitive
+    subgroup of S6, isomorphic to $A_5$.
+
+    Notes
+    =====
+
+    This was computed using :py:func:`~.find_transitive_subgroups_of_S6`.
+
+    """
+    G = PermutationGroup(
+        Permutation(0, 4, 5)(1, 3, 2), Permutation(0, 4, 3, 1, 5))
+    set_alternating_group_properties(G, 5, 6)
+    return G
+
+
+def PGL2F5():
+    r"""
+    Return a representation of the group $PGL_2(\mathbb{F}_5)$, as a transitive
+    subgroup of S6, isomorphic to $S_5$.
+
+    Notes
+    =====
+
+    See [1], Page 325.
+
+    """
+    G = PermutationGroup(
+        Permutation(0, 1, 2, 3, 4), Permutation(0, 5)(1, 2)(3, 4))
+    set_symmetric_group_properties(G, 5, 6)
+    return G
+
+
+def find_transitive_subgroups_of_S6(*targets, print_report=False):
+    r"""
+    Search for certain transitive subgroups of $S_6$.
+
+    The symmetric group $S_6$ has 16 different transitive subgroups, up to
+    conjugacy. Some are more easily constructed than others. For example, the
+    dihedral group $D_6$ is immediately found, but it is not at all obvious how
+    to realize $S_4$ or $S_5$ *transitively* within $S_6$.
+
+    In some cases there are well-known constructions that can be used. For
+    example, $S_5$ is isomorphic to $PGL_2(\mathbb{F}_5)$, which acts in a
+    natural way on the projective line $P^1(\mathbb{F}_5)$, a set of order 6.
+
+    In absence of such special constructions however, we can simply search for
+    generators. For example, transitive instances of $A_4$ and $S_4$ can be
+    found within $S_6$ in this way.
+
+    Once we are engaged in such searches, it may then be easier (if less
+    elegant) to find even those groups like $S_5$ that do have special
+    constructions, by mere search.
+
+    This function locates generators for transitive instances in $S_6$ of the
+    following subgroups:
+
+    * $A_4$
+    * $S_4^-$ ($S_4$ not contained within $A_6$)
+    * $S_4^+$ ($S_4$ contained within $A_6$)
+    * $A_4 \times C_2$
+    * $S_4 \times C_2$
+    * $G_{18}   = C_3^2 \rtimes C_2$
+    * $G_{36}^- = C_3^2 \rtimes C_2^2$
+    * $G_{36}^+ = C_3^2 \rtimes C_4$
+    * $G_{72}   = C_3^2 \rtimes D_4$
+    * $A_5$
+    * $S_5$
+
+    Note: Each of these groups also has a dedicated function in this module
+    that returns the group immediately, using generators that were found by
+    this search procedure.
+
+    The search procedure serves as a record of how these generators were
+    found. Also, due to randomness in the generation of the elements of
+    permutation groups, it can be called again, in order to (probably) get
+    different generators for the same groups.
+
+    Parameters
+    ==========
+
+    targets : list of :py:class:`~.S6TransitiveSubgroups` values
+        The groups you want to find.
+
+    print_report : bool (default False)
+        If True, print to stdout the generators found for each group.
+
+    Returns
+    =======
+
+    dict
+        mapping each name in *targets* to the :py:class:`~.PermutationGroup`
+        that was found
+
+    References
+    ==========
+
+    .. [2] https://en.wikipedia.org/wiki/Projective_linear_group#Exceptional_isomorphisms
+    .. [3] https://en.wikipedia.org/wiki/Automorphisms_of_the_symmetric_and_alternating_groups#PGL(2,5)
+
+    """
+    def elts_by_order(G):
+        """Sort the elements of a group by their order. """
+        elts = defaultdict(list)
+        for g in G.elements:
+            elts[g.order()].append(g)
+        return elts
+
+    def order_profile(G, name=None):
+        """Determine how many elements a group has, of each order. """
+        elts = elts_by_order(G)
+        profile = {o:len(e) for o, e in elts.items()}
+        if name:
+            print(f'{name}: ' + ' '.join(f'{len(profile[r])}@{r}' for r in sorted(profile.keys())))
+        return profile
+
+    S6 = SymmetricGroup(6)
+    A6 = AlternatingGroup(6)
+    S6_by_order = elts_by_order(S6)
+
+    def search(existing_gens, needed_gen_orders, order, alt=None, profile=None, anti_profile=None):
+        """
+        Find a transitive subgroup of S6.
+
+        Parameters
+        ==========
+
+        existing_gens : list of Permutation
+            Optionally empty list of generators that must be in the group.
+
+        needed_gen_orders : list of positive int
+            Nonempty list of the orders of the additional generators that are
+            to be found.
+
+        order: int
+            The order of the group being sought.
+
+        alt: bool, None
+            If True, require the group to be contained in A6.
+            If False, require the group not to be contained in A6.
+
+        profile : dict
+            If given, the group's order profile must equal this.
+
+        anti_profile : dict
+            If given, the group's order profile must *not* equal this.
+
+        """
+        for gens in itertools.product(*[S6_by_order[n] for n in needed_gen_orders]):
+            if len(set(gens)) < len(gens):
+                continue
+            G = PermutationGroup(existing_gens + list(gens))
+            if G.order() == order and G.is_transitive():
+                if alt is not None and G.is_subgroup(A6) != alt:
+                    continue
+                if profile and order_profile(G) != profile:
+                    continue
+                if anti_profile and order_profile(G) == anti_profile:
+                    continue
+                return G
+
+    def match_known_group(G, alt=None):
+        needed = [g.order() for g in G.generators]
+        return search([], needed, G.order(), alt=alt, profile=order_profile(G))
+
+    found = {}
+
+    def finish_up(name, G):
+        found[name] = G
+        if print_report:
+            print("=" * 40)
+            print(f"{name}:")
+            print(G.generators)
+
+    if S6TransitiveSubgroups.A4 in targets or S6TransitiveSubgroups.A4xC2 in targets:
+        A4_in_S6 = match_known_group(AlternatingGroup(4))
+        finish_up(S6TransitiveSubgroups.A4, A4_in_S6)
+
+    if S6TransitiveSubgroups.S4m in targets or S6TransitiveSubgroups.S4xC2 in targets:
+        S4m_in_S6 = match_known_group(SymmetricGroup(4), alt=False)
+        finish_up(S6TransitiveSubgroups.S4m, S4m_in_S6)
+
+    if S6TransitiveSubgroups.S4p in targets:
+        S4p_in_S6 = match_known_group(SymmetricGroup(4), alt=True)
+        finish_up(S6TransitiveSubgroups.S4p, S4p_in_S6)
+
+    if S6TransitiveSubgroups.A4xC2 in targets:
+        A4xC2_in_S6 = search(A4_in_S6.generators, [2], 24, anti_profile=order_profile(SymmetricGroup(4)))
+        finish_up(S6TransitiveSubgroups.A4xC2, A4xC2_in_S6)
+
+    if S6TransitiveSubgroups.S4xC2 in targets:
+        S4xC2_in_S6 = search(S4m_in_S6.generators, [2], 48)
+        finish_up(S6TransitiveSubgroups.S4xC2, S4xC2_in_S6)
+
+    # For the normal factor N = C3^2 in any of the G_n subgroups, we take one
+    # obvious instance of C3^2 in S6:
+    N_gens = [Permutation(5)(0, 1, 2), Permutation(5)(3, 4, 5)]
+
+    if S6TransitiveSubgroups.G18 in targets:
+        G18_in_S6 = search(N_gens, [2], 18)
+        finish_up(S6TransitiveSubgroups.G18, G18_in_S6)
+
+    if S6TransitiveSubgroups.G36m in targets:
+        G36m_in_S6 = search(N_gens, [2, 2], 36, alt=False)
+        finish_up(S6TransitiveSubgroups.G36m, G36m_in_S6)
+
+    if S6TransitiveSubgroups.G36p in targets:
+        G36p_in_S6 = search(N_gens, [4], 36, alt=True)
+        finish_up(S6TransitiveSubgroups.G36p, G36p_in_S6)
+
+    if S6TransitiveSubgroups.G72 in targets:
+        G72_in_S6 = search(N_gens, [4, 2], 72)
+        finish_up(S6TransitiveSubgroups.G72, G72_in_S6)
+
+    # The PSL2(F5) and PGL2(F5) subgroups are isomorphic to A5 and S5, resp.
+
+    if S6TransitiveSubgroups.PSL2F5 in targets:
+        PSL2F5_in_S6 = match_known_group(AlternatingGroup(5))
+        finish_up(S6TransitiveSubgroups.PSL2F5, PSL2F5_in_S6)
+
+    if S6TransitiveSubgroups.PGL2F5 in targets:
+        PGL2F5_in_S6 = match_known_group(SymmetricGroup(5))
+        finish_up(S6TransitiveSubgroups.PGL2F5, PGL2F5_in_S6)
+
+    # There is little need to "search" for any of the groups C6, S3, D6, A6,
+    # or S6, since they all have obvious realizations within S6. However, we
+    # support them here just in case a random representation is desired.
+
+    if S6TransitiveSubgroups.C6 in targets:
+        C6 = match_known_group(CyclicGroup(6))
+        finish_up(S6TransitiveSubgroups.C6, C6)
+
+    if S6TransitiveSubgroups.S3 in targets:
+        S3 = match_known_group(SymmetricGroup(3))
+        finish_up(S6TransitiveSubgroups.S3, S3)
+
+    if S6TransitiveSubgroups.D6 in targets:
+        D6 = match_known_group(DihedralGroup(6))
+        finish_up(S6TransitiveSubgroups.D6, D6)
+
+    if S6TransitiveSubgroups.A6 in targets:
+        A6 = match_known_group(A6)
+        finish_up(S6TransitiveSubgroups.A6, A6)
+
+    if S6TransitiveSubgroups.S6 in targets:
+        S6 = match_known_group(S6)
+        finish_up(S6TransitiveSubgroups.S6, S6)
+
+    return found

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/group_constructs.py

@@ -0,0 +1,61 @@
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.combinatorics.permutations import Permutation
+from sympy.utilities.iterables import uniq
+
+_af_new = Permutation._af_new
+
+
+def DirectProduct(*groups):
+    """
+    Returns the direct product of several groups as a permutation group.
+
+    Explanation
+    ===========
+
+    This is implemented much like the __mul__ procedure for taking the direct
+    product of two permutation groups, but the idea of shifting the
+    generators is realized in the case of an arbitrary number of groups.
+    A call to DirectProduct(G1, G2, ..., Gn) is generally expected to be faster
+    than a call to G1*G2*...*Gn (and thus the need for this algorithm).
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.group_constructs import DirectProduct
+    >>> from sympy.combinatorics.named_groups import CyclicGroup
+    >>> C = CyclicGroup(4)
+    >>> G = DirectProduct(C, C, C)
+    >>> G.order()
+    64
+
+    See Also
+    ========
+
+    sympy.combinatorics.perm_groups.PermutationGroup.__mul__
+
+    """
+    degrees = []
+    gens_count = []
+    total_degree = 0
+    total_gens = 0
+    for group in groups:
+        current_deg = group.degree
+        current_num_gens = len(group.generators)
+        degrees.append(current_deg)
+        total_degree += current_deg
+        gens_count.append(current_num_gens)
+        total_gens += current_num_gens
+    array_gens = []
+    for i in range(total_gens):
+        array_gens.append(list(range(total_degree)))
+    current_gen = 0
+    current_deg = 0
+    for i in range(len(gens_count)):
+        for j in range(current_gen, current_gen + gens_count[i]):
+            gen = ((groups[i].generators)[j - current_gen]).array_form
+            array_gens[j][current_deg:current_deg + degrees[i]] = \
+                [x + current_deg for x in gen]
+        current_gen += gens_count[i]
+        current_deg += degrees[i]
+    perm_gens = list(uniq([_af_new(list(a)) for a in array_gens]))
+    return PermutationGroup(perm_gens, dups=False)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/group_numbers.py

@@ -0,0 +1,118 @@
+from sympy.core import Integer, Pow, Mod
+from sympy import factorint
+
+
+def is_nilpotent_number(n):
+    """
+    Check whether `n` is a nilpotent number. A number `n` is said to be
+    nilpotent if and only if every finite group of order `n` is nilpotent.
+    For more information see [1]_.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.group_numbers import is_nilpotent_number
+    >>> from sympy import randprime
+    >>> is_nilpotent_number(21)
+    False
+    >>> is_nilpotent_number(randprime(1, 30)**12)
+    True
+
+    References
+    ==========
+
+    .. [1] Pakianathan, J., Shankar, K., *Nilpotent Numbers*,
+            The American Mathematical Monthly, 107(7), 631-634.
+
+
+    """
+    if n <= 0 or int(n) != n:
+        raise ValueError("n must be a positive integer, not %i" % n)
+
+    n = Integer(n)
+    prime_factors = list(factorint(n).items())
+    is_nilpotent = True
+    for p_j, a_j in prime_factors:
+        for p_i, a_i in prime_factors:
+            if any([Mod(Pow(p_i, k), p_j) == 1 for k in range(1, a_i + 1)]):
+                is_nilpotent = False
+                break
+        if not is_nilpotent:
+            break
+
+    return is_nilpotent
+
+
+def is_abelian_number(n):
+    """
+    Check whether `n` is an abelian number. A number `n` is said to be abelian
+    if and only if every finite group of order `n` is abelian. For more
+    information see [1]_.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.group_numbers import is_abelian_number
+    >>> from sympy import randprime
+    >>> is_abelian_number(4)
+    True
+    >>> is_abelian_number(randprime(1, 2000)**2)
+    True
+    >>> is_abelian_number(60)
+    False
+
+    References
+    ==========
+
+    .. [1] Pakianathan, J., Shankar, K., *Nilpotent Numbers*,
+            The American Mathematical Monthly, 107(7), 631-634.
+
+
+    """
+    if n <= 0 or int(n) != n:
+        raise ValueError("n must be a positive integer, not %i" % n)
+
+    n = Integer(n)
+    if not is_nilpotent_number(n):
+        return False
+
+    prime_factors = list(factorint(n).items())
+    is_abelian = all(a_i < 3 for p_i, a_i in prime_factors)
+    return is_abelian
+
+
+def is_cyclic_number(n):
+    """
+    Check whether `n` is a cyclic number. A number `n` is said to be cyclic
+    if and only if every finite group of order `n` is cyclic. For more
+    information see [1]_.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.group_numbers import is_cyclic_number
+    >>> from sympy import randprime
+    >>> is_cyclic_number(15)
+    True
+    >>> is_cyclic_number(randprime(1, 2000)**2)
+    False
+    >>> is_cyclic_number(4)
+    False
+
+    References
+    ==========
+
+    .. [1] Pakianathan, J., Shankar, K., *Nilpotent Numbers*,
+            The American Mathematical Monthly, 107(7), 631-634.
+
+    """
+    if n <= 0 or int(n) != n:
+        raise ValueError("n must be a positive integer, not %i" % n)
+
+    n = Integer(n)
+    if not is_nilpotent_number(n):
+        return False
+
+    prime_factors = list(factorint(n).items())
+    is_cyclic = all(a_i < 2 for p_i, a_i in prime_factors)
+    return is_cyclic

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/homomorphisms.py

@@ -0,0 +1,549 @@
+import itertools
+from sympy.combinatorics.fp_groups import FpGroup, FpSubgroup, simplify_presentation
+from sympy.combinatorics.free_groups import FreeGroup
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.core.numbers import igcd
+from sympy.ntheory.factor_ import totient
+from sympy.core.singleton import S
+
+class GroupHomomorphism:
+    '''
+    A class representing group homomorphisms. Instantiate using `homomorphism()`.
+
+    References
+    ==========
+
+    .. [1] Holt, D., Eick, B. and O'Brien, E. (2005). Handbook of computational group theory.
+
+    '''
+
+    def __init__(self, domain, codomain, images):
+        self.domain = domain
+        self.codomain = codomain
+        self.images = images
+        self._inverses = None
+        self._kernel = None
+        self._image = None
+
+    def _invs(self):
+        '''
+        Return a dictionary with `{gen: inverse}` where `gen` is a rewriting
+        generator of `codomain` (e.g. strong generator for permutation groups)
+        and `inverse` is an element of its preimage
+
+        '''
+        image = self.image()
+        inverses = {}
+        for k in list(self.images.keys()):
+            v = self.images[k]
+            if not (v in inverses
+                    or v.is_identity):
+                inverses[v] = k
+        if isinstance(self.codomain, PermutationGroup):
+            gens = image.strong_gens
+        else:
+            gens = image.generators
+        for g in gens:
+            if g in inverses or g.is_identity:
+                continue
+            w = self.domain.identity
+            if isinstance(self.codomain, PermutationGroup):
+                parts = image._strong_gens_slp[g][::-1]
+            else:
+                parts = g
+            for s in parts:
+                if s in inverses:
+                    w = w*inverses[s]
+                else:
+                    w = w*inverses[s**-1]**-1
+            inverses[g] = w
+
+        return inverses
+
+    def invert(self, g):
+        '''
+        Return an element of the preimage of ``g`` or of each element
+        of ``g`` if ``g`` is a list.
+
+        Explanation
+        ===========
+
+        If the codomain is an FpGroup, the inverse for equal
+        elements might not always be the same unless the FpGroup's
+        rewriting system is confluent. However, making a system
+        confluent can be time-consuming. If it's important, try
+        `self.codomain.make_confluent()` first.
+
+        '''
+        from sympy.combinatorics import Permutation
+        from sympy.combinatorics.free_groups import FreeGroupElement
+        if isinstance(g, (Permutation, FreeGroupElement)):
+            if isinstance(self.codomain, FpGroup):
+                g = self.codomain.reduce(g)
+            if self._inverses is None:
+                self._inverses = self._invs()
+            image = self.image()
+            w = self.domain.identity
+            if isinstance(self.codomain, PermutationGroup):
+                gens = image.generator_product(g)[::-1]
+            else:
+                gens = g
+            # the following can't be "for s in gens:"
+            # because that would be equivalent to
+            # "for s in gens.array_form:" when g is
+            # a FreeGroupElement. On the other hand,
+            # when you call gens by index, the generator
+            # (or inverse) at position i is returned.
+            for i in range(len(gens)):
+                s = gens[i]
+                if s.is_identity:
+                    continue
+                if s in self._inverses:
+                    w = w*self._inverses[s]
+                else:
+                    w = w*self._inverses[s**-1]**-1
+            return w
+        elif isinstance(g, list):
+            return [self.invert(e) for e in g]
+
+    def kernel(self):
+        '''
+        Compute the kernel of `self`.
+
+        '''
+        if self._kernel is None:
+            self._kernel = self._compute_kernel()
+        return self._kernel
+
+    def _compute_kernel(self):
+        G = self.domain
+        G_order = G.order()
+        if G_order is S.Infinity:
+            raise NotImplementedError(
+                "Kernel computation is not implemented for infinite groups")
+        gens = []
+        if isinstance(G, PermutationGroup):
+            K = PermutationGroup(G.identity)
+        else:
+            K = FpSubgroup(G, gens, normal=True)
+        i = self.image().order()
+        while K.order()*i != G_order:
+            r = G.random()
+            k = r*self.invert(self(r))**-1
+            if k not in K:
+                gens.append(k)
+                if isinstance(G, PermutationGroup):
+                    K = PermutationGroup(gens)
+                else:
+                    K = FpSubgroup(G, gens, normal=True)
+        return K
+
+    def image(self):
+        '''
+        Compute the image of `self`.
+
+        '''
+        if self._image is None:
+            values = list(set(self.images.values()))
+            if isinstance(self.codomain, PermutationGroup):
+                self._image = self.codomain.subgroup(values)
+            else:
+                self._image = FpSubgroup(self.codomain, values)
+        return self._image
+
+    def _apply(self, elem):
+        '''
+        Apply `self` to `elem`.
+
+        '''
+        if elem not in self.domain:
+            if isinstance(elem, (list, tuple)):
+                return [self._apply(e) for e in elem]
+            raise ValueError("The supplied element does not belong to the domain")
+        if elem.is_identity:
+            return self.codomain.identity
+        else:
+            images = self.images
+            value = self.codomain.identity
+            if isinstance(self.domain, PermutationGroup):
+                gens = self.domain.generator_product(elem, original=True)
+                for g in gens:
+                    if g in self.images:
+                        value = images[g]*value
+                    else:
+                        value = images[g**-1]**-1*value
+            else:
+                i = 0
+                for _, p in elem.array_form:
+                    if p < 0:
+                        g = elem[i]**-1
+                    else:
+                        g = elem[i]
+                    value = value*images[g]**p
+                    i += abs(p)
+        return value
+
+    def __call__(self, elem):
+        return self._apply(elem)
+
+    def is_injective(self):
+        '''
+        Check if the homomorphism is injective
+
+        '''
+        return self.kernel().order() == 1
+
+    def is_surjective(self):
+        '''
+        Check if the homomorphism is surjective
+
+        '''
+        im = self.image().order()
+        oth = self.codomain.order()
+        if im is S.Infinity and oth is S.Infinity:
+            return None
+        else:
+            return im == oth
+
+    def is_isomorphism(self):
+        '''
+        Check if `self` is an isomorphism.
+
+        '''
+        return self.is_injective() and self.is_surjective()
+
+    def is_trivial(self):
+        '''
+        Check is `self` is a trivial homomorphism, i.e. all elements
+        are mapped to the identity.
+
+        '''
+        return self.image().order() == 1
+
+    def compose(self, other):
+        '''
+        Return the composition of `self` and `other`, i.e.
+        the homomorphism phi such that for all g in the domain
+        of `other`, phi(g) = self(other(g))
+
+        '''
+        if not other.image().is_subgroup(self.domain):
+            raise ValueError("The image of `other` must be a subgroup of "
+                    "the domain of `self`")
+        images = {g: self(other(g)) for g in other.images}
+        return GroupHomomorphism(other.domain, self.codomain, images)
+
+    def restrict_to(self, H):
+        '''
+        Return the restriction of the homomorphism to the subgroup `H`
+        of the domain.
+
+        '''
+        if not isinstance(H, PermutationGroup) or not H.is_subgroup(self.domain):
+            raise ValueError("Given H is not a subgroup of the domain")
+        domain = H
+        images = {g: self(g) for g in H.generators}
+        return GroupHomomorphism(domain, self.codomain, images)
+
+    def invert_subgroup(self, H):
+        '''
+        Return the subgroup of the domain that is the inverse image
+        of the subgroup ``H`` of the homomorphism image
+
+        '''
+        if not H.is_subgroup(self.image()):
+            raise ValueError("Given H is not a subgroup of the image")
+        gens = []
+        P = PermutationGroup(self.image().identity)
+        for h in H.generators:
+            h_i = self.invert(h)
+            if h_i not in P:
+                gens.append(h_i)
+                P = PermutationGroup(gens)
+            for k in self.kernel().generators:
+                if k*h_i not in P:
+                    gens.append(k*h_i)
+                    P = PermutationGroup(gens)
+        return P
+
+def homomorphism(domain, codomain, gens, images=(), check=True):
+    '''
+    Create (if possible) a group homomorphism from the group ``domain``
+    to the group ``codomain`` defined by the images of the domain's
+    generators ``gens``. ``gens`` and ``images`` can be either lists or tuples
+    of equal sizes. If ``gens`` is a proper subset of the group's generators,
+    the unspecified generators will be mapped to the identity. If the
+    images are not specified, a trivial homomorphism will be created.
+
+    If the given images of the generators do not define a homomorphism,
+    an exception is raised.
+
+    If ``check`` is ``False``, do not check whether the given images actually
+    define a homomorphism.
+
+    '''
+    if not isinstance(domain, (PermutationGroup, FpGroup, FreeGroup)):
+        raise TypeError("The domain must be a group")
+    if not isinstance(codomain, (PermutationGroup, FpGroup, FreeGroup)):
+        raise TypeError("The codomain must be a group")
+
+    generators = domain.generators
+    if not all(g in generators for g in gens):
+        raise ValueError("The supplied generators must be a subset of the domain's generators")
+    if not all(g in codomain for g in images):
+        raise ValueError("The images must be elements of the codomain")
+
+    if images and len(images) != len(gens):
+        raise ValueError("The number of images must be equal to the number of generators")
+
+    gens = list(gens)
+    images = list(images)
+
+    images.extend([codomain.identity]*(len(generators)-len(images)))
+    gens.extend([g for g in generators if g not in gens])
+    images = dict(zip(gens,images))
+
+    if check and not _check_homomorphism(domain, codomain, images):
+        raise ValueError("The given images do not define a homomorphism")
+    return GroupHomomorphism(domain, codomain, images)
+
+def _check_homomorphism(domain, codomain, images):
+    """
+    Check that a given mapping of generators to images defines a homomorphism.
+
+    Parameters
+    ==========
+    domain : PermutationGroup, FpGroup, FreeGroup
+    codomain : PermutationGroup, FpGroup, FreeGroup
+    images : dict
+        The set of keys must be equal to domain.generators.
+        The values must be elements of the codomain.
+
+    """
+    pres = domain if hasattr(domain, 'relators') else domain.presentation()
+    rels = pres.relators
+    gens = pres.generators
+    symbols = [g.ext_rep[0] for g in gens]
+    symbols_to_domain_generators = dict(zip(symbols, domain.generators))
+    identity = codomain.identity
+
+    def _image(r):
+        w = identity
+        for symbol, power in r.array_form:
+            g = symbols_to_domain_generators[symbol]
+            w *= images[g]**power
+        return w
+
+    for r in rels:
+        if isinstance(codomain, FpGroup):
+            s = codomain.equals(_image(r), identity)
+            if s is None:
+                # only try to make the rewriting system
+                # confluent when it can't determine the
+                # truth of equality otherwise
+                success = codomain.make_confluent()
+                s = codomain.equals(_image(r), identity)
+                if s is None and not success:
+                    raise RuntimeError("Can't determine if the images "
+                        "define a homomorphism. Try increasing "
+                        "the maximum number of rewriting rules "
+                        "(group._rewriting_system.set_max(new_value); "
+                        "the current value is stored in group._rewriting"
+                        "_system.maxeqns)")
+        else:
+            s = _image(r).is_identity
+        if not s:
+            return False
+    return True
+
+def orbit_homomorphism(group, omega):
+    '''
+    Return the homomorphism induced by the action of the permutation
+    group ``group`` on the set ``omega`` that is closed under the action.
+
+    '''
+    from sympy.combinatorics import Permutation
+    from sympy.combinatorics.named_groups import SymmetricGroup
+    codomain = SymmetricGroup(len(omega))
+    identity = codomain.identity
+    omega = list(omega)
+    images = {g: identity*Permutation([omega.index(o^g) for o in omega]) for g in group.generators}
+    group._schreier_sims(base=omega)
+    H = GroupHomomorphism(group, codomain, images)
+    if len(group.basic_stabilizers) > len(omega):
+        H._kernel = group.basic_stabilizers[len(omega)]
+    else:
+        H._kernel = PermutationGroup([group.identity])
+    return H
+
+def block_homomorphism(group, blocks):
+    '''
+    Return the homomorphism induced by the action of the permutation
+    group ``group`` on the block system ``blocks``. The latter should be
+    of the same form as returned by the ``minimal_block`` method for
+    permutation groups, namely a list of length ``group.degree`` where
+    the i-th entry is a representative of the block i belongs to.
+
+    '''
+    from sympy.combinatorics import Permutation
+    from sympy.combinatorics.named_groups import SymmetricGroup
+
+    n = len(blocks)
+
+    # number the blocks; m is the total number,
+    # b is such that b[i] is the number of the block i belongs to,
+    # p is the list of length m such that p[i] is the representative
+    # of the i-th block
+    m = 0
+    p = []
+    b = [None]*n
+    for i in range(n):
+        if blocks[i] == i:
+            p.append(i)
+            b[i] = m
+            m += 1
+    for i in range(n):
+        b[i] = b[blocks[i]]
+
+    codomain = SymmetricGroup(m)
+    # the list corresponding to the identity permutation in codomain
+    identity = range(m)
+    images = {g: Permutation([b[p[i]^g] for i in identity]) for g in group.generators}
+    H = GroupHomomorphism(group, codomain, images)
+    return H
+
+def group_isomorphism(G, H, isomorphism=True):
+    '''
+    Compute an isomorphism between 2 given groups.
+
+    Parameters
+    ==========
+
+    G : A finite ``FpGroup`` or a ``PermutationGroup``.
+        First group.
+
+    H : A finite ``FpGroup`` or a ``PermutationGroup``
+        Second group.
+
+    isomorphism : bool
+        This is used to avoid the computation of homomorphism
+        when the user only wants to check if there exists
+        an isomorphism between the groups.
+
+    Returns
+    =======
+
+    If isomorphism = False -- Returns a boolean.
+    If isomorphism = True  -- Returns a boolean and an isomorphism between `G` and `H`.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics import free_group, Permutation
+    >>> from sympy.combinatorics.perm_groups import PermutationGroup
+    >>> from sympy.combinatorics.fp_groups import FpGroup
+    >>> from sympy.combinatorics.homomorphisms import group_isomorphism
+    >>> from sympy.combinatorics.named_groups import DihedralGroup, AlternatingGroup
+
+    >>> D = DihedralGroup(8)
+    >>> p = Permutation(0, 1, 2, 3, 4, 5, 6, 7)
+    >>> P = PermutationGroup(p)
+    >>> group_isomorphism(D, P)
+    (False, None)
+
+    >>> F, a, b = free_group("a, b")
+    >>> G = FpGroup(F, [a**3, b**3, (a*b)**2])
+    >>> H = AlternatingGroup(4)
+    >>> (check, T) = group_isomorphism(G, H)
+    >>> check
+    True
+    >>> T(b*a*b**-1*a**-1*b**-1)
+    (0 2 3)
+
+    Notes
+    =====
+
+    Uses the approach suggested by Robert Tarjan to compute the isomorphism between two groups.
+    First, the generators of ``G`` are mapped to the elements of ``H`` and
+    we check if the mapping induces an isomorphism.
+
+    '''
+    if not isinstance(G, (PermutationGroup, FpGroup)):
+        raise TypeError("The group must be a PermutationGroup or an FpGroup")
+    if not isinstance(H, (PermutationGroup, FpGroup)):
+        raise TypeError("The group must be a PermutationGroup or an FpGroup")
+
+    if isinstance(G, FpGroup) and isinstance(H, FpGroup):
+        G = simplify_presentation(G)
+        H = simplify_presentation(H)
+        # Two infinite FpGroups with the same generators are isomorphic
+        # when the relators are same but are ordered differently.
+        if G.generators == H.generators and (G.relators).sort() == (H.relators).sort():
+            if not isomorphism:
+                return True
+            return (True, homomorphism(G, H, G.generators, H.generators))
+
+    #  `_H` is the permutation group isomorphic to `H`.
+    _H = H
+    g_order = G.order()
+    h_order = H.order()
+
+    if g_order is S.Infinity:
+        raise NotImplementedError("Isomorphism methods are not implemented for infinite groups.")
+
+    if isinstance(H, FpGroup):
+        if h_order is S.Infinity:
+            raise NotImplementedError("Isomorphism methods are not implemented for infinite groups.")
+        _H, h_isomorphism = H._to_perm_group()
+
+    if (g_order != h_order) or (G.is_abelian != H.is_abelian):
+        if not isomorphism:
+            return False
+        return (False, None)
+
+    if not isomorphism:
+        # Two groups of the same cyclic numbered order
+        # are isomorphic to each other.
+        n = g_order
+        if (igcd(n, totient(n))) == 1:
+            return True
+
+    # Match the generators of `G` with subsets of `_H`
+    gens = list(G.generators)
+    for subset in itertools.permutations(_H, len(gens)):
+        images = list(subset)
+        images.extend([_H.identity]*(len(G.generators)-len(images)))
+        _images = dict(zip(gens,images))
+        if _check_homomorphism(G, _H, _images):
+            if isinstance(H, FpGroup):
+                images = h_isomorphism.invert(images)
+            T =  homomorphism(G, H, G.generators, images, check=False)
+            if T.is_isomorphism():
+                # It is a valid isomorphism
+                if not isomorphism:
+                    return True
+                return (True, T)
+
+    if not isomorphism:
+        return False
+    return (False, None)
+
+def is_isomorphic(G, H):
+    '''
+    Check if the groups are isomorphic to each other
+
+    Parameters
+    ==========
+
+    G : A finite ``FpGroup`` or a ``PermutationGroup``
+        First group.
+
+    H : A finite ``FpGroup`` or a ``PermutationGroup``
+        Second group.
+
+    Returns
+    =======
+
+    boolean
+    '''
+    return group_isomorphism(G, H, isomorphism=False)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/prufer.py

@@ -0,0 +1,436 @@
+from sympy.core import Basic
+from sympy.core.containers import Tuple
+from sympy.tensor.array import Array
+from sympy.core.sympify import _sympify
+from sympy.utilities.iterables import flatten, iterable
+from sympy.utilities.misc import as_int
+
+from collections import defaultdict
+
+
+class Prufer(Basic):
+    """
+    The Prufer correspondence is an algorithm that describes the
+    bijection between labeled trees and the Prufer code. A Prufer
+    code of a labeled tree is unique up to isomorphism and has
+    a length of n - 2.
+
+    Prufer sequences were first used by Heinz Prufer to give a
+    proof of Cayley's formula.
+
+    References
+    ==========
+
+    .. [1] https://mathworld.wolfram.com/LabeledTree.html
+
+    """
+    _prufer_repr = None
+    _tree_repr = None
+    _nodes = None
+    _rank = None
+
+    @property
+    def prufer_repr(self):
+        """Returns Prufer sequence for the Prufer object.
+
+        This sequence is found by removing the highest numbered vertex,
+        recording the node it was attached to, and continuing until only
+        two vertices remain. The Prufer sequence is the list of recorded nodes.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]]).prufer_repr
+        [3, 3, 3, 4]
+        >>> Prufer([1, 0, 0]).prufer_repr
+        [1, 0, 0]
+
+        See Also
+        ========
+
+        to_prufer
+
+        """
+        if self._prufer_repr is None:
+            self._prufer_repr = self.to_prufer(self._tree_repr[:], self.nodes)
+        return self._prufer_repr
+
+    @property
+    def tree_repr(self):
+        """Returns the tree representation of the Prufer object.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]]).tree_repr
+        [[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]]
+        >>> Prufer([1, 0, 0]).tree_repr
+        [[1, 2], [0, 1], [0, 3], [0, 4]]
+
+        See Also
+        ========
+
+        to_tree
+
+        """
+        if self._tree_repr is None:
+            self._tree_repr = self.to_tree(self._prufer_repr[:])
+        return self._tree_repr
+
+    @property
+    def nodes(self):
+        """Returns the number of nodes in the tree.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]]).nodes
+        6
+        >>> Prufer([1, 0, 0]).nodes
+        5
+
+        """
+        return self._nodes
+
+    @property
+    def rank(self):
+        """Returns the rank of the Prufer sequence.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> p = Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]])
+        >>> p.rank
+        778
+        >>> p.next(1).rank
+        779
+        >>> p.prev().rank
+        777
+
+        See Also
+        ========
+
+        prufer_rank, next, prev, size
+
+        """
+        if self._rank is None:
+            self._rank = self.prufer_rank()
+        return self._rank
+
+    @property
+    def size(self):
+        """Return the number of possible trees of this Prufer object.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer([0]*4).size == Prufer([6]*4).size == 1296
+        True
+
+        See Also
+        ========
+
+        prufer_rank, rank, next, prev
+
+        """
+        return self.prev(self.rank).prev().rank + 1
+
+    @staticmethod
+    def to_prufer(tree, n):
+        """Return the Prufer sequence for a tree given as a list of edges where
+        ``n`` is the number of nodes in the tree.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> a = Prufer([[0, 1], [0, 2], [0, 3]])
+        >>> a.prufer_repr
+        [0, 0]
+        >>> Prufer.to_prufer([[0, 1], [0, 2], [0, 3]], 4)
+        [0, 0]
+
+        See Also
+        ========
+        prufer_repr: returns Prufer sequence of a Prufer object.
+
+        """
+        d = defaultdict(int)
+        L = []
+        for edge in tree:
+            # Increment the value of the corresponding
+            # node in the degree list as we encounter an
+            # edge involving it.
+            d[edge[0]] += 1
+            d[edge[1]] += 1
+        for i in range(n - 2):
+            # find the smallest leaf
+            for x in range(n):
+                if d[x] == 1:
+                    break
+            # find the node it was connected to
+            y = None
+            for edge in tree:
+                if x == edge[0]:
+                    y = edge[1]
+                elif x == edge[1]:
+                    y = edge[0]
+                if y is not None:
+                    break
+            # record and update
+            L.append(y)
+            for j in (x, y):
+                d[j] -= 1
+                if not d[j]:
+                    d.pop(j)
+            tree.remove(edge)
+        return L
+
+    @staticmethod
+    def to_tree(prufer):
+        """Return the tree (as a list of edges) of the given Prufer sequence.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> a = Prufer([0, 2], 4)
+        >>> a.tree_repr
+        [[0, 1], [0, 2], [2, 3]]
+        >>> Prufer.to_tree([0, 2])
+        [[0, 1], [0, 2], [2, 3]]
+
+        References
+        ==========
+
+        .. [1] https://hamberg.no/erlend/posts/2010-11-06-prufer-sequence-compact-tree-representation.html
+
+        See Also
+        ========
+        tree_repr: returns tree representation of a Prufer object.
+
+        """
+        tree = []
+        last = []
+        n = len(prufer) + 2
+        d = defaultdict(lambda: 1)
+        for p in prufer:
+            d[p] += 1
+        for i in prufer:
+            for j in range(n):
+            # find the smallest leaf (degree = 1)
+                if d[j] == 1:
+                    break
+            # (i, j) is the new edge that we append to the tree
+            # and remove from the degree dictionary
+            d[i] -= 1
+            d[j] -= 1
+            tree.append(sorted([i, j]))
+        last = [i for i in range(n) if d[i] == 1] or [0, 1]
+        tree.append(last)
+
+        return tree
+
+    @staticmethod
+    def edges(*runs):
+        """Return a list of edges and the number of nodes from the given runs
+        that connect nodes in an integer-labelled tree.
+
+        All node numbers will be shifted so that the minimum node is 0. It is
+        not a problem if edges are repeated in the runs; only unique edges are
+        returned. There is no assumption made about what the range of the node
+        labels should be, but all nodes from the smallest through the largest
+        must be present.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer.edges([1, 2, 3], [2, 4, 5]) # a T
+        ([[0, 1], [1, 2], [1, 3], [3, 4]], 5)
+
+        Duplicate edges are removed:
+
+        >>> Prufer.edges([0, 1, 2, 3], [1, 4, 5], [1, 4, 6]) # a K
+        ([[0, 1], [1, 2], [1, 4], [2, 3], [4, 5], [4, 6]], 7)
+
+        """
+        e = set()
+        nmin = runs[0][0]
+        for r in runs:
+            for i in range(len(r) - 1):
+                a, b = r[i: i + 2]
+                if b < a:
+                    a, b = b, a
+                e.add((a, b))
+        rv = []
+        got = set()
+        nmin = nmax = None
+        for ei in e:
+            for i in ei:
+                got.add(i)
+            nmin = min(ei[0], nmin) if nmin is not None else ei[0]
+            nmax = max(ei[1], nmax) if nmax is not None else ei[1]
+            rv.append(list(ei))
+        missing = set(range(nmin, nmax + 1)) - got
+        if missing:
+            missing = [i + nmin for i in missing]
+            if len(missing) == 1:
+                msg = 'Node %s is missing.' % missing.pop()
+            else:
+                msg = 'Nodes %s are missing.' % sorted(missing)
+            raise ValueError(msg)
+        if nmin != 0:
+            for i, ei in enumerate(rv):
+                rv[i] = [n - nmin for n in ei]
+            nmax -= nmin
+        return sorted(rv), nmax + 1
+
+    def prufer_rank(self):
+        """Computes the rank of a Prufer sequence.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> a = Prufer([[0, 1], [0, 2], [0, 3]])
+        >>> a.prufer_rank()
+        0
+
+        See Also
+        ========
+
+        rank, next, prev, size
+
+        """
+        r = 0
+        p = 1
+        for i in range(self.nodes - 3, -1, -1):
+            r += p*self.prufer_repr[i]
+            p *= self.nodes
+        return r
+
+    @classmethod
+    def unrank(self, rank, n):
+        """Finds the unranked Prufer sequence.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> Prufer.unrank(0, 4)
+        Prufer([0, 0])
+
+        """
+        n, rank = as_int(n), as_int(rank)
+        L = defaultdict(int)
+        for i in range(n - 3, -1, -1):
+            L[i] = rank % n
+            rank = (rank - L[i])//n
+        return Prufer([L[i] for i in range(len(L))])
+
+    def __new__(cls, *args, **kw_args):
+        """The constructor for the Prufer object.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+
+        A Prufer object can be constructed from a list of edges:
+
+        >>> a = Prufer([[0, 1], [0, 2], [0, 3]])
+        >>> a.prufer_repr
+        [0, 0]
+
+        If the number of nodes is given, no checking of the nodes will
+        be performed; it will be assumed that nodes 0 through n - 1 are
+        present:
+
+        >>> Prufer([[0, 1], [0, 2], [0, 3]], 4)
+        Prufer([[0, 1], [0, 2], [0, 3]], 4)
+
+        A Prufer object can be constructed from a Prufer sequence:
+
+        >>> b = Prufer([1, 3])
+        >>> b.tree_repr
+        [[0, 1], [1, 3], [2, 3]]
+
+        """
+        arg0 = Array(args[0]) if args[0] else Tuple()
+        args = (arg0,) + tuple(_sympify(arg) for arg in args[1:])
+        ret_obj = Basic.__new__(cls, *args, **kw_args)
+        args = [list(args[0])]
+        if args[0] and iterable(args[0][0]):
+            if not args[0][0]:
+                raise ValueError(
+                    'Prufer expects at least one edge in the tree.')
+            if len(args) > 1:
+                nnodes = args[1]
+            else:
+                nodes = set(flatten(args[0]))
+                nnodes = max(nodes) + 1
+                if nnodes != len(nodes):
+                    missing = set(range(nnodes)) - nodes
+                    if len(missing) == 1:
+                        msg = 'Node %s is missing.' % missing.pop()
+                    else:
+                        msg = 'Nodes %s are missing.' % sorted(missing)
+                    raise ValueError(msg)
+            ret_obj._tree_repr = [list(i) for i in args[0]]
+            ret_obj._nodes = nnodes
+        else:
+            ret_obj._prufer_repr = args[0]
+            ret_obj._nodes = len(ret_obj._prufer_repr) + 2
+        return ret_obj
+
+    def next(self, delta=1):
+        """Generates the Prufer sequence that is delta beyond the current one.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> a = Prufer([[0, 1], [0, 2], [0, 3]])
+        >>> b = a.next(1) # == a.next()
+        >>> b.tree_repr
+        [[0, 2], [0, 1], [1, 3]]
+        >>> b.rank
+        1
+
+        See Also
+        ========
+
+        prufer_rank, rank, prev, size
+
+        """
+        return Prufer.unrank(self.rank + delta, self.nodes)
+
+    def prev(self, delta=1):
+        """Generates the Prufer sequence that is -delta before the current one.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics.prufer import Prufer
+        >>> a = Prufer([[0, 1], [1, 2], [2, 3], [1, 4]])
+        >>> a.rank
+        36
+        >>> b = a.prev()
+        >>> b
+        Prufer([1, 2, 0])
+        >>> b.rank
+        35
+
+        See Also
+        ========
+
+        prufer_rank, rank, next, size
+
+        """
+        return Prufer.unrank(self.rank -delta, self.nodes)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/subsets.py

@@ -0,0 +1,619 @@
+from itertools import combinations
+
+from sympy.combinatorics.graycode import GrayCode
+
+
+class Subset():
+    """
+    Represents a basic subset object.
+
+    Explanation
+    ===========
+
+    We generate subsets using essentially two techniques,
+    binary enumeration and lexicographic enumeration.
+    The Subset class takes two arguments, the first one
+    describes the initial subset to consider and the second
+    describes the superset.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics import Subset
+    >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+    >>> a.next_binary().subset
+    ['b']
+    >>> a.prev_binary().subset
+    ['c']
+    """
+
+    _rank_binary = None
+    _rank_lex = None
+    _rank_graycode = None
+    _subset = None
+    _superset = None
+
+    def __new__(cls, subset, superset):
+        """
+        Default constructor.
+
+        It takes the ``subset`` and its ``superset`` as its parameters.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.subset
+        ['c', 'd']
+        >>> a.superset
+        ['a', 'b', 'c', 'd']
+        >>> a.size
+        2
+        """
+        if len(subset) > len(superset):
+            raise ValueError('Invalid arguments have been provided. The '
+                             'superset must be larger than the subset.')
+        for elem in subset:
+            if elem not in superset:
+                raise ValueError('The superset provided is invalid as it does '
+                                 'not contain the element {}'.format(elem))
+        obj = object.__new__(cls)
+        obj._subset = subset
+        obj._superset = superset
+        return obj
+
+    def __eq__(self, other):
+        """Return a boolean indicating whether a == b on the basis of
+        whether both objects are of the class Subset and if the values
+        of the subset and superset attributes are the same.
+        """
+        if not isinstance(other, Subset):
+            return NotImplemented
+        return self.subset == other.subset and self.superset == other.superset
+
+    def iterate_binary(self, k):
+        """
+        This is a helper function. It iterates over the
+        binary subsets by ``k`` steps. This variable can be
+        both positive or negative.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.iterate_binary(-2).subset
+        ['d']
+        >>> a = Subset(['a', 'b', 'c'], ['a', 'b', 'c', 'd'])
+        >>> a.iterate_binary(2).subset
+        []
+
+        See Also
+        ========
+
+        next_binary, prev_binary
+        """
+        bin_list = Subset.bitlist_from_subset(self.subset, self.superset)
+        n = (int(''.join(bin_list), 2) + k) % 2**self.superset_size
+        bits = bin(n)[2:].rjust(self.superset_size, '0')
+        return Subset.subset_from_bitlist(self.superset, bits)
+
+    def next_binary(self):
+        """
+        Generates the next binary ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.next_binary().subset
+        ['b']
+        >>> a = Subset(['a', 'b', 'c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.next_binary().subset
+        []
+
+        See Also
+        ========
+
+        prev_binary, iterate_binary
+        """
+        return self.iterate_binary(1)
+
+    def prev_binary(self):
+        """
+        Generates the previous binary ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([], ['a', 'b', 'c', 'd'])
+        >>> a.prev_binary().subset
+        ['a', 'b', 'c', 'd']
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.prev_binary().subset
+        ['c']
+
+        See Also
+        ========
+
+        next_binary, iterate_binary
+        """
+        return self.iterate_binary(-1)
+
+    def next_lexicographic(self):
+        """
+        Generates the next lexicographically ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.next_lexicographic().subset
+        ['d']
+        >>> a = Subset(['d'], ['a', 'b', 'c', 'd'])
+        >>> a.next_lexicographic().subset
+        []
+
+        See Also
+        ========
+
+        prev_lexicographic
+        """
+        i = self.superset_size - 1
+        indices = Subset.subset_indices(self.subset, self.superset)
+
+        if i in indices:
+            if i - 1 in indices:
+                indices.remove(i - 1)
+            else:
+                indices.remove(i)
+                i = i - 1
+                while i >= 0 and i not in indices:
+                    i = i - 1
+                if i >= 0:
+                    indices.remove(i)
+                    indices.append(i+1)
+        else:
+            while i not in indices and i >= 0:
+                i = i - 1
+            indices.append(i + 1)
+
+        ret_set = []
+        super_set = self.superset
+        for i in indices:
+            ret_set.append(super_set[i])
+        return Subset(ret_set, super_set)
+
+    def prev_lexicographic(self):
+        """
+        Generates the previous lexicographically ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([], ['a', 'b', 'c', 'd'])
+        >>> a.prev_lexicographic().subset
+        ['d']
+        >>> a = Subset(['c','d'], ['a', 'b', 'c', 'd'])
+        >>> a.prev_lexicographic().subset
+        ['c']
+
+        See Also
+        ========
+
+        next_lexicographic
+        """
+        i = self.superset_size - 1
+        indices = Subset.subset_indices(self.subset, self.superset)
+
+        while i >= 0 and i not in indices:
+            i = i - 1
+
+        if i == 0 or i - 1 in indices:
+            indices.remove(i)
+        else:
+            if i >= 0:
+                indices.remove(i)
+                indices.append(i - 1)
+            indices.append(self.superset_size - 1)
+
+        ret_set = []
+        super_set = self.superset
+        for i in indices:
+            ret_set.append(super_set[i])
+        return Subset(ret_set, super_set)
+
+    def iterate_graycode(self, k):
+        """
+        Helper function used for prev_gray and next_gray.
+        It performs ``k`` step overs to get the respective Gray codes.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([1, 2, 3], [1, 2, 3, 4])
+        >>> a.iterate_graycode(3).subset
+        [1, 4]
+        >>> a.iterate_graycode(-2).subset
+        [1, 2, 4]
+
+        See Also
+        ========
+
+        next_gray, prev_gray
+        """
+        unranked_code = GrayCode.unrank(self.superset_size,
+                                       (self.rank_gray + k) % self.cardinality)
+        return Subset.subset_from_bitlist(self.superset,
+                                          unranked_code)
+
+    def next_gray(self):
+        """
+        Generates the next Gray code ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([1, 2, 3], [1, 2, 3, 4])
+        >>> a.next_gray().subset
+        [1, 3]
+
+        See Also
+        ========
+
+        iterate_graycode, prev_gray
+        """
+        return self.iterate_graycode(1)
+
+    def prev_gray(self):
+        """
+        Generates the previous Gray code ordered subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([2, 3, 4], [1, 2, 3, 4, 5])
+        >>> a.prev_gray().subset
+        [2, 3, 4, 5]
+
+        See Also
+        ========
+
+        iterate_graycode, next_gray
+        """
+        return self.iterate_graycode(-1)
+
+    @property
+    def rank_binary(self):
+        """
+        Computes the binary ordered rank.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset([], ['a','b','c','d'])
+        >>> a.rank_binary
+        0
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.rank_binary
+        3
+
+        See Also
+        ========
+
+        iterate_binary, unrank_binary
+        """
+        if self._rank_binary is None:
+            self._rank_binary = int("".join(
+                Subset.bitlist_from_subset(self.subset,
+                                           self.superset)), 2)
+        return self._rank_binary
+
+    @property
+    def rank_lexicographic(self):
+        """
+        Computes the lexicographic ranking of the subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.rank_lexicographic
+        14
+        >>> a = Subset([2, 4, 5], [1, 2, 3, 4, 5, 6])
+        >>> a.rank_lexicographic
+        43
+        """
+        if self._rank_lex is None:
+            def _ranklex(self, subset_index, i, n):
+                if subset_index == [] or i > n:
+                    return 0
+                if i in subset_index:
+                    subset_index.remove(i)
+                    return 1 + _ranklex(self, subset_index, i + 1, n)
+                return 2**(n - i - 1) + _ranklex(self, subset_index, i + 1, n)
+            indices = Subset.subset_indices(self.subset, self.superset)
+            self._rank_lex = _ranklex(self, indices, 0, self.superset_size)
+        return self._rank_lex
+
+    @property
+    def rank_gray(self):
+        """
+        Computes the Gray code ranking of the subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c','d'], ['a','b','c','d'])
+        >>> a.rank_gray
+        2
+        >>> a = Subset([2, 4, 5], [1, 2, 3, 4, 5, 6])
+        >>> a.rank_gray
+        27
+
+        See Also
+        ========
+
+        iterate_graycode, unrank_gray
+        """
+        if self._rank_graycode is None:
+            bits = Subset.bitlist_from_subset(self.subset, self.superset)
+            self._rank_graycode = GrayCode(len(bits), start=bits).rank
+        return self._rank_graycode
+
+    @property
+    def subset(self):
+        """
+        Gets the subset represented by the current instance.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.subset
+        ['c', 'd']
+
+        See Also
+        ========
+
+        superset, size, superset_size, cardinality
+        """
+        return self._subset
+
+    @property
+    def size(self):
+        """
+        Gets the size of the subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.size
+        2
+
+        See Also
+        ========
+
+        subset, superset, superset_size, cardinality
+        """
+        return len(self.subset)
+
+    @property
+    def superset(self):
+        """
+        Gets the superset of the subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.superset
+        ['a', 'b', 'c', 'd']
+
+        See Also
+        ========
+
+        subset, size, superset_size, cardinality
+        """
+        return self._superset
+
+    @property
+    def superset_size(self):
+        """
+        Returns the size of the superset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.superset_size
+        4
+
+        See Also
+        ========
+
+        subset, superset, size, cardinality
+        """
+        return len(self.superset)
+
+    @property
+    def cardinality(self):
+        """
+        Returns the number of all possible subsets.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        >>> a.cardinality
+        16
+
+        See Also
+        ========
+
+        subset, superset, size, superset_size
+        """
+        return 2**(self.superset_size)
+
+    @classmethod
+    def subset_from_bitlist(self, super_set, bitlist):
+        """
+        Gets the subset defined by the bitlist.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> Subset.subset_from_bitlist(['a', 'b', 'c', 'd'], '0011').subset
+        ['c', 'd']
+
+        See Also
+        ========
+
+        bitlist_from_subset
+        """
+        if len(super_set) != len(bitlist):
+            raise ValueError("The sizes of the lists are not equal")
+        ret_set = []
+        for i in range(len(bitlist)):
+            if bitlist[i] == '1':
+                ret_set.append(super_set[i])
+        return Subset(ret_set, super_set)
+
+    @classmethod
+    def bitlist_from_subset(self, subset, superset):
+        """
+        Gets the bitlist corresponding to a subset.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> Subset.bitlist_from_subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+        '0011'
+
+        See Also
+        ========
+
+        subset_from_bitlist
+        """
+        bitlist = ['0'] * len(superset)
+        if isinstance(subset, Subset):
+            subset = subset.subset
+        for i in Subset.subset_indices(subset, superset):
+            bitlist[i] = '1'
+        return ''.join(bitlist)
+
+    @classmethod
+    def unrank_binary(self, rank, superset):
+        """
+        Gets the binary ordered subset of the specified rank.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> Subset.unrank_binary(4, ['a', 'b', 'c', 'd']).subset
+        ['b']
+
+        See Also
+        ========
+
+        iterate_binary, rank_binary
+        """
+        bits = bin(rank)[2:].rjust(len(superset), '0')
+        return Subset.subset_from_bitlist(superset, bits)
+
+    @classmethod
+    def unrank_gray(self, rank, superset):
+        """
+        Gets the Gray code ordered subset of the specified rank.
+
+        Examples
+        ========
+
+        >>> from sympy.combinatorics import Subset
+        >>> Subset.unrank_gray(4, ['a', 'b', 'c']).subset
+        ['a', 'b']
+        >>> Subset.unrank_gray(0, ['a', 'b', 'c']).subset
+        []
+
+        See Also
+        ========
+
+        iterate_graycode, rank_gray
+        """
+        graycode_bitlist = GrayCode.unrank(len(superset), rank)
+        return Subset.subset_from_bitlist(superset, graycode_bitlist)
+
+    @classmethod
+    def subset_indices(self, subset, superset):
+        """Return indices of subset in superset in a list; the list is empty
+        if all elements of ``subset`` are not in ``superset``.
+
+        Examples
+        ========
+
+            >>> from sympy.combinatorics import Subset
+            >>> superset = [1, 3, 2, 5, 4]
+            >>> Subset.subset_indices([3, 2, 1], superset)
+            [1, 2, 0]
+            >>> Subset.subset_indices([1, 6], superset)
+            []
+            >>> Subset.subset_indices([], superset)
+            []
+
+        """
+        a, b = superset, subset
+        sb = set(b)
+        d = {}
+        for i, ai in enumerate(a):
+            if ai in sb:
+                d[ai] = i
+                sb.remove(ai)
+                if not sb:
+                    break
+        else:
+            return []
+        return [d[bi] for bi in b]
+
+
+def ksubsets(superset, k):
+    """
+    Finds the subsets of size ``k`` in lexicographic order.
+
+    This uses the itertools generator.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.subsets import ksubsets
+    >>> list(ksubsets([1, 2, 3], 2))
+    [(1, 2), (1, 3), (2, 3)]
+    >>> list(ksubsets([1, 2, 3, 4, 5], 2))
+    [(1, 2), (1, 3), (1, 4), (1, 5), (2, 3), (2, 4), \
+    (2, 5), (3, 4), (3, 5), (4, 5)]
+
+    See Also
+    ========
+
+    Subset
+    """
+    return combinations(superset, k)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tensor_can.py

@@ -0,0 +1,1190 @@
+from sympy.combinatorics.permutations import Permutation, _af_rmul, \
+    _af_invert, _af_new
+from sympy.combinatorics.perm_groups import PermutationGroup, _orbit, \
+    _orbit_transversal
+from sympy.combinatorics.util import _distribute_gens_by_base, \
+    _orbits_transversals_from_bsgs
+
+"""
+    References for tensor canonicalization:
+
+    [1] R. Portugal "Algorithmic simplification of tensor expressions",
+        J. Phys. A 32 (1999) 7779-7789
+
+    [2] R. Portugal, B.F. Svaiter "Group-theoretic Approach for Symbolic
+        Tensor Manipulation: I. Free Indices"
+        arXiv:math-ph/0107031v1
+
+    [3] L.R.U. Manssur, R. Portugal "Group-theoretic Approach for Symbolic
+        Tensor Manipulation: II. Dummy Indices"
+        arXiv:math-ph/0107032v1
+
+    [4] xperm.c part of XPerm written by J. M. Martin-Garcia
+        http://www.xact.es/index.html
+"""
+
+
+def dummy_sgs(dummies, sym, n):
+    """
+    Return the strong generators for dummy indices.
+
+    Parameters
+    ==========
+
+    dummies : List of dummy indices.
+        `dummies[2k], dummies[2k+1]` are paired indices.
+        In base form, the dummy indices are always in
+        consecutive positions.
+    sym : symmetry under interchange of contracted dummies::
+        * None  no symmetry
+        * 0     commuting
+        * 1     anticommuting
+
+    n : number of indices
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import dummy_sgs
+    >>> dummy_sgs(list(range(2, 8)), 0, 8)
+    [[0, 1, 3, 2, 4, 5, 6, 7, 8, 9], [0, 1, 2, 3, 5, 4, 6, 7, 8, 9],
+     [0, 1, 2, 3, 4, 5, 7, 6, 8, 9], [0, 1, 4, 5, 2, 3, 6, 7, 8, 9],
+     [0, 1, 2, 3, 6, 7, 4, 5, 8, 9]]
+    """
+    if len(dummies) > n:
+        raise ValueError("List too large")
+    res = []
+    # exchange of contravariant and covariant indices
+    if sym is not None:
+        for j in dummies[::2]:
+            a = list(range(n + 2))
+            if sym == 1:
+                a[n] = n + 1
+                a[n + 1] = n
+            a[j], a[j + 1] = a[j + 1], a[j]
+            res.append(a)
+    # rename dummy indices
+    for j in dummies[:-3:2]:
+        a = list(range(n + 2))
+        a[j:j + 4] = a[j + 2], a[j + 3], a[j], a[j + 1]
+        res.append(a)
+    return res
+
+
+def _min_dummies(dummies, sym, indices):
+    """
+    Return list of minima of the orbits of indices in group of dummies.
+    See ``double_coset_can_rep`` for the description of ``dummies`` and ``sym``.
+    ``indices`` is the initial list of dummy indices.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import _min_dummies
+    >>> _min_dummies([list(range(2, 8))], [0], list(range(10)))
+    [0, 1, 2, 2, 2, 2, 2, 2, 8, 9]
+    """
+    num_types = len(sym)
+    m = [min(dx) if dx else None for dx in dummies]
+    res = indices[:]
+    for i in range(num_types):
+        for c, i in enumerate(indices):
+            for j in range(num_types):
+                if i in dummies[j]:
+                    res[c] = m[j]
+                    break
+    return res
+
+
+def _trace_S(s, j, b, S_cosets):
+    """
+    Return the representative h satisfying s[h[b]] == j
+
+    If there is not such a representative return None
+    """
+    for h in S_cosets[b]:
+        if s[h[b]] == j:
+            return h
+    return None
+
+
+def _trace_D(gj, p_i, Dxtrav):
+    """
+    Return the representative h satisfying h[gj] == p_i
+
+    If there is not such a representative return None
+    """
+    for h in Dxtrav:
+        if h[gj] == p_i:
+            return h
+    return None
+
+
+def _dumx_remove(dumx, dumx_flat, p0):
+    """
+    remove p0 from dumx
+    """
+    res = []
+    for dx in dumx:
+        if p0 not in dx:
+            res.append(dx)
+            continue
+        k = dx.index(p0)
+        if k % 2 == 0:
+            p0_paired = dx[k + 1]
+        else:
+            p0_paired = dx[k - 1]
+        dx.remove(p0)
+        dx.remove(p0_paired)
+        dumx_flat.remove(p0)
+        dumx_flat.remove(p0_paired)
+        res.append(dx)
+
+
+def transversal2coset(size, base, transversal):
+    a = []
+    j = 0
+    for i in range(size):
+        if i in base:
+            a.append(sorted(transversal[j].values()))
+            j += 1
+        else:
+            a.append([list(range(size))])
+    j = len(a) - 1
+    while a[j] == [list(range(size))]:
+        j -= 1
+    return a[:j + 1]
+
+
+def double_coset_can_rep(dummies, sym, b_S, sgens, S_transversals, g):
+    r"""
+    Butler-Portugal algorithm for tensor canonicalization with dummy indices.
+
+    Parameters
+    ==========
+
+      dummies
+        list of lists of dummy indices,
+        one list for each type of index;
+        the dummy indices are put in order contravariant, covariant
+        [d0, -d0, d1, -d1, ...].
+
+      sym
+        list of the symmetries of the index metric for each type.
+
+      possible symmetries of the metrics
+              * 0     symmetric
+              * 1     antisymmetric
+              * None  no symmetry
+
+      b_S
+        base of a minimal slot symmetry BSGS.
+
+      sgens
+        generators of the slot symmetry BSGS.
+
+      S_transversals
+        transversals for the slot BSGS.
+
+      g
+        permutation representing the tensor.
+
+    Returns
+    =======
+
+    Return 0 if the tensor is zero, else return the array form of
+    the permutation representing the canonical form of the tensor.
+
+    Notes
+    =====
+
+    A tensor with dummy indices can be represented in a number
+    of equivalent ways which typically grows exponentially with
+    the number of indices. To be able to establish if two tensors
+    with many indices are equal becomes computationally very slow
+    in absence of an efficient algorithm.
+
+    The Butler-Portugal algorithm [3] is an efficient algorithm to
+    put tensors in canonical form, solving the above problem.
+
+    Portugal observed that a tensor can be represented by a permutation,
+    and that the class of tensors equivalent to it under slot and dummy
+    symmetries is equivalent to the double coset `D*g*S`
+    (Note: in this documentation we use the conventions for multiplication
+    of permutations p, q with (p*q)(i) = p[q[i]] which is opposite
+    to the one used in the Permutation class)
+
+    Using the algorithm by Butler to find a representative of the
+    double coset one can find a canonical form for the tensor.
+
+    To see this correspondence,
+    let `g` be a permutation in array form; a tensor with indices `ind`
+    (the indices including both the contravariant and the covariant ones)
+    can be written as
+
+    `t = T(ind[g[0]], \dots, ind[g[n-1]])`,
+
+    where `n = len(ind)`;
+    `g` has size `n + 2`, the last two indices for the sign of the tensor
+    (trick introduced in [4]).
+
+    A slot symmetry transformation `s` is a permutation acting on the slots
+    `t \rightarrow T(ind[(g*s)[0]], \dots, ind[(g*s)[n-1]])`
+
+    A dummy symmetry transformation acts on `ind`
+    `t \rightarrow T(ind[(d*g)[0]], \dots, ind[(d*g)[n-1]])`
+
+    Being interested only in the transformations of the tensor under
+    these symmetries, one can represent the tensor by `g`, which transforms
+    as
+
+    `g -> d*g*s`, so it belongs to the coset `D*g*S`, or in other words
+    to the set of all permutations allowed by the slot and dummy symmetries.
+
+    Let us explain the conventions by an example.
+
+    Given a tensor `T^{d3 d2 d1}{}_{d1 d2 d3}` with the slot symmetries
+          `T^{a0 a1 a2 a3 a4 a5} = -T^{a2 a1 a0 a3 a4 a5}`
+
+          `T^{a0 a1 a2 a3 a4 a5} = -T^{a4 a1 a2 a3 a0 a5}`
+
+    and symmetric metric, find the tensor equivalent to it which
+    is the lowest under the ordering of indices:
+    lexicographic ordering `d1, d2, d3` and then contravariant
+    before covariant index; that is the canonical form of the tensor.
+
+    The canonical form is `-T^{d1 d2 d3}{}_{d1 d2 d3}`
+    obtained using `T^{a0 a1 a2 a3 a4 a5} = -T^{a2 a1 a0 a3 a4 a5}`.
+
+    To convert this problem in the input for this function,
+    use the following ordering of the index names
+    (- for covariant for short) `d1, -d1, d2, -d2, d3, -d3`
+
+    `T^{d3 d2 d1}{}_{d1 d2 d3}` corresponds to `g = [4, 2, 0, 1, 3, 5, 6, 7]`
+    where the last two indices are for the sign
+
+    `sgens = [Permutation(0, 2)(6, 7), Permutation(0, 4)(6, 7)]`
+
+    sgens[0] is the slot symmetry `-(0, 2)`
+    `T^{a0 a1 a2 a3 a4 a5} = -T^{a2 a1 a0 a3 a4 a5}`
+
+    sgens[1] is the slot symmetry `-(0, 4)`
+    `T^{a0 a1 a2 a3 a4 a5} = -T^{a4 a1 a2 a3 a0 a5}`
+
+    The dummy symmetry group D is generated by the strong base generators
+    `[(0, 1), (2, 3), (4, 5), (0, 2)(1, 3), (0, 4)(1, 5)]`
+    where the first three interchange covariant and contravariant
+    positions of the same index (d1 <-> -d1) and the last two interchange
+    the dummy indices themselves (d1 <-> d2).
+
+    The dummy symmetry acts from the left
+    `d = [1, 0, 2, 3, 4, 5, 6, 7]`  exchange `d1 \leftrightarrow -d1`
+    `T^{d3 d2 d1}{}_{d1 d2 d3} == T^{d3 d2}{}_{d1}{}^{d1}{}_{d2 d3}`
+
+    `g=[4, 2, 0, 1, 3, 5, 6, 7]  -> [4, 2, 1, 0, 3, 5, 6, 7] = _af_rmul(d, g)`
+    which differs from `_af_rmul(g, d)`.
+
+    The slot symmetry acts from the right
+    `s = [2, 1, 0, 3, 4, 5, 7, 6]`  exchanges slots 0 and 2 and changes sign
+    `T^{d3 d2 d1}{}_{d1 d2 d3} == -T^{d1 d2 d3}{}_{d1 d2 d3}`
+
+    `g=[4,2,0,1,3,5,6,7]  -> [0, 2, 4, 1, 3, 5, 7, 6] = _af_rmul(g, s)`
+
+    Example in which the tensor is zero, same slot symmetries as above:
+    `T^{d2}{}_{d1 d3}{}^{d1 d3}{}_{d2}`
+
+    `= -T^{d3}{}_{d1 d3}{}^{d1 d2}{}_{d2}`   under slot symmetry `-(0,4)`;
+
+    `= T_{d3 d1}{}^{d3}{}^{d1 d2}{}_{d2}`    under slot symmetry `-(0,2)`;
+
+    `= T^{d3}{}_{d1 d3}{}^{d1 d2}{}_{d2}`    symmetric metric;
+
+    `= 0`  since two of these lines have tensors differ only for the sign.
+
+    The double coset D*g*S consists of permutations `h = d*g*s` corresponding
+    to equivalent tensors; if there are two `h` which are the same apart
+    from the sign, return zero; otherwise
+    choose as representative the tensor with indices
+    ordered lexicographically according to `[d1, -d1, d2, -d2, d3, -d3]`
+    that is ``rep = min(D*g*S) = min([d*g*s for d in D for s in S])``
+
+    The indices are fixed one by one; first choose the lowest index
+    for slot 0, then the lowest remaining index for slot 1, etc.
+    Doing this one obtains a chain of stabilizers
+
+    `S \rightarrow S_{b0} \rightarrow S_{b0,b1} \rightarrow \dots` and
+    `D \rightarrow D_{p0} \rightarrow D_{p0,p1} \rightarrow \dots`
+
+    where ``[b0, b1, ...] = range(b)`` is a base of the symmetric group;
+    the strong base `b_S` of S is an ordered sublist of it;
+    therefore it is sufficient to compute once the
+    strong base generators of S using the Schreier-Sims algorithm;
+    the stabilizers of the strong base generators are the
+    strong base generators of the stabilizer subgroup.
+
+    ``dbase = [p0, p1, ...]`` is not in general in lexicographic order,
+    so that one must recompute the strong base generators each time;
+    however this is trivial, there is no need to use the Schreier-Sims
+    algorithm for D.
+
+    The algorithm keeps a TAB of elements `(s_i, d_i, h_i)`
+    where `h_i = d_i \times g \times s_i` satisfying `h_i[j] = p_j` for `0 \le j < i`
+    starting from `s_0 = id, d_0 = id, h_0 = g`.
+
+    The equations `h_0[0] = p_0, h_1[1] = p_1, \dots` are solved in this order,
+    choosing each time the lowest possible value of p_i
+
+    For `j < i`
+    `d_i*g*s_i*S_{b_0, \dots, b_{i-1}}*b_j = D_{p_0, \dots, p_{i-1}}*p_j`
+    so that for dx in `D_{p_0,\dots,p_{i-1}}` and sx in
+    `S_{base[0], \dots, base[i-1]}` one has `dx*d_i*g*s_i*sx*b_j = p_j`
+
+    Search for dx, sx such that this equation holds for `j = i`;
+    it can be written as `s_i*sx*b_j = J, dx*d_i*g*J = p_j`
+    `sx*b_j = s_i**-1*J; sx = trace(s_i**-1, S_{b_0,...,b_{i-1}})`
+    `dx**-1*p_j = d_i*g*J; dx = trace(d_i*g*J, D_{p_0,...,p_{i-1}})`
+
+    `s_{i+1} = s_i*trace(s_i**-1*J, S_{b_0,...,b_{i-1}})`
+    `d_{i+1} = trace(d_i*g*J, D_{p_0,...,p_{i-1}})**-1*d_i`
+    `h_{i+1}*b_i = d_{i+1}*g*s_{i+1}*b_i = p_i`
+
+    `h_n*b_j = p_j` for all j, so that `h_n` is the solution.
+
+    Add the found `(s, d, h)` to TAB1.
+
+    At the end of the iteration sort TAB1 with respect to the `h`;
+    if there are two consecutive `h` in TAB1 which differ only for the
+    sign, the tensor is zero, so return 0;
+    if there are two consecutive `h` which are equal, keep only one.
+
+    Then stabilize the slot generators under `i` and the dummy generators
+    under `p_i`.
+
+    Assign `TAB = TAB1` at the end of the iteration step.
+
+    At the end `TAB` contains a unique `(s, d, h)`, since all the slots
+    of the tensor `h` have been fixed to have the minimum value according
+    to the symmetries. The algorithm returns `h`.
+
+    It is important that the slot BSGS has lexicographic minimal base,
+    otherwise there is an `i` which does not belong to the slot base
+    for which `p_i` is fixed by the dummy symmetry only, while `i`
+    is not invariant from the slot stabilizer, so `p_i` is not in
+    general the minimal value.
+
+    This algorithm differs slightly from the original algorithm [3]:
+      the canonical form is minimal lexicographically, and
+      the BSGS has minimal base under lexicographic order.
+      Equal tensors `h` are eliminated from TAB.
+
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.permutations import Permutation
+    >>> from sympy.combinatorics.tensor_can import double_coset_can_rep, get_transversals
+    >>> gens = [Permutation(x) for x in [[2, 1, 0, 3, 4, 5, 7, 6], [4, 1, 2, 3, 0, 5, 7, 6]]]
+    >>> base = [0, 2]
+    >>> g = Permutation([4, 2, 0, 1, 3, 5, 6, 7])
+    >>> transversals = get_transversals(base, gens)
+    >>> double_coset_can_rep([list(range(6))], [0], base, gens, transversals, g)
+    [0, 1, 2, 3, 4, 5, 7, 6]
+
+    >>> g = Permutation([4, 1, 3, 0, 5, 2, 6, 7])
+    >>> double_coset_can_rep([list(range(6))], [0], base, gens, transversals, g)
+    0
+    """
+    size = g.size
+    g = g.array_form
+    num_dummies = size - 2
+    indices = list(range(num_dummies))
+    all_metrics_with_sym = not any(_ is None for _ in sym)
+    num_types = len(sym)
+    dumx = dummies[:]
+    dumx_flat = []
+    for dx in dumx:
+        dumx_flat.extend(dx)
+    b_S = b_S[:]
+    sgensx = [h._array_form for h in sgens]
+    if b_S:
+        S_transversals = transversal2coset(size, b_S, S_transversals)
+    # strong generating set for D
+    dsgsx = []
+    for i in range(num_types):
+        dsgsx.extend(dummy_sgs(dumx[i], sym[i], num_dummies))
+    idn = list(range(size))
+    # TAB = list of entries (s, d, h) where h = _af_rmuln(d,g,s)
+    # for short, in the following d*g*s means _af_rmuln(d,g,s)
+    TAB = [(idn, idn, g)]
+    for i in range(size - 2):
+        b = i
+        testb = b in b_S and sgensx
+        if testb:
+            sgensx1 = [_af_new(_) for _ in sgensx]
+            deltab = _orbit(size, sgensx1, b)
+        else:
+            deltab = {b}
+        # p1 = min(IMAGES) = min(Union D_p*h*deltab for h in TAB)
+        if all_metrics_with_sym:
+            md = _min_dummies(dumx, sym, indices)
+        else:
+            md = [min(_orbit(size, [_af_new(
+                ddx) for ddx in dsgsx], ii)) for ii in range(size - 2)]
+
+        p_i = min([min([md[h[x]] for x in deltab]) for s, d, h in TAB])
+        dsgsx1 = [_af_new(_) for _ in dsgsx]
+        Dxtrav = _orbit_transversal(size, dsgsx1, p_i, False, af=True) \
+            if dsgsx else None
+        if Dxtrav:
+            Dxtrav = [_af_invert(x) for x in Dxtrav]
+        # compute the orbit of p_i
+        for ii in range(num_types):
+            if p_i in dumx[ii]:
+                # the orbit is made by all the indices in dum[ii]
+                if sym[ii] is not None:
+                    deltap = dumx[ii]
+                else:
+                    # the orbit is made by all the even indices if p_i
+                    # is even, by all the odd indices if p_i is odd
+                    p_i_index = dumx[ii].index(p_i) % 2
+                    deltap = dumx[ii][p_i_index::2]
+                break
+        else:
+            deltap = [p_i]
+        TAB1 = []
+        while TAB:
+            s, d, h = TAB.pop()
+            if min([md[h[x]] for x in deltab]) != p_i:
+                continue
+            deltab1 = [x for x in deltab if md[h[x]] == p_i]
+            # NEXT = s*deltab1 intersection (d*g)**-1*deltap
+            dg = _af_rmul(d, g)
+            dginv = _af_invert(dg)
+            sdeltab = [s[x] for x in deltab1]
+            gdeltap = [dginv[x] for x in deltap]
+            NEXT = [x for x in sdeltab if x in gdeltap]
+            # d, s satisfy
+            # d*g*s*base[i-1] = p_{i-1}; using the stabilizers
+            # d*g*s*S_{base[0],...,base[i-1]}*base[i-1] =
+            # D_{p_0,...,p_{i-1}}*p_{i-1}
+            # so that to find d1, s1 satisfying d1*g*s1*b = p_i
+            # one can look for dx in D_{p_0,...,p_{i-1}} and
+            # sx in S_{base[0],...,base[i-1]}
+            # d1 = dx*d; s1 = s*sx
+            # d1*g*s1*b = dx*d*g*s*sx*b = p_i
+            for j in NEXT:
+                if testb:
+                    # solve s1*b = j with s1 = s*sx for some element sx
+                    # of the stabilizer of ..., base[i-1]
+                    # sx*b = s**-1*j; sx = _trace_S(s, j,...)
+                    # s1 = s*trace_S(s**-1*j,...)
+                    s1 = _trace_S(s, j, b, S_transversals)
+                    if not s1:
+                        continue
+                    else:
+                        s1 = [s[ix] for ix in s1]
+                else:
+                    s1 = s
+                # assert s1[b] == j  # invariant
+                # solve d1*g*j = p_i with d1 = dx*d for some element dg
+                # of the stabilizer of ..., p_{i-1}
+                # dx**-1*p_i = d*g*j; dx**-1 = trace_D(d*g*j,...)
+                # d1 = trace_D(d*g*j,...)**-1*d
+                # to save an inversion in the inner loop; notice we did
+                # Dxtrav = [perm_af_invert(x) for x in Dxtrav] out of the loop
+                if Dxtrav:
+                    d1 = _trace_D(dg[j], p_i, Dxtrav)
+                    if not d1:
+                        continue
+                else:
+                    if p_i != dg[j]:
+                        continue
+                    d1 = idn
+                assert d1[dg[j]] == p_i  # invariant
+                d1 = [d1[ix] for ix in d]
+                h1 = [d1[g[ix]] for ix in s1]
+                # assert h1[b] == p_i  # invariant
+                TAB1.append((s1, d1, h1))
+
+        # if TAB contains equal permutations, keep only one of them;
+        # if TAB contains equal permutations up to the sign, return 0
+        TAB1.sort(key=lambda x: x[-1])
+        prev = [0] * size
+        while TAB1:
+            s, d, h = TAB1.pop()
+            if h[:-2] == prev[:-2]:
+                if h[-1] != prev[-1]:
+                    return 0
+            else:
+                TAB.append((s, d, h))
+            prev = h
+
+        # stabilize the SGS
+        sgensx = [h for h in sgensx if h[b] == b]
+        if b in b_S:
+            b_S.remove(b)
+        _dumx_remove(dumx, dumx_flat, p_i)
+        dsgsx = []
+        for i in range(num_types):
+            dsgsx.extend(dummy_sgs(dumx[i], sym[i], num_dummies))
+    return TAB[0][-1]
+
+
+def canonical_free(base, gens, g, num_free):
+    """
+    Canonicalization of a tensor with respect to free indices
+    choosing the minimum with respect to lexicographical ordering
+    in the free indices.
+
+    Explanation
+    ===========
+
+    ``base``, ``gens``  BSGS for slot permutation group
+    ``g``               permutation representing the tensor
+    ``num_free``        number of free indices
+    The indices must be ordered with first the free indices
+
+    See explanation in double_coset_can_rep
+    The algorithm is a variation of the one given in [2].
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics import Permutation
+    >>> from sympy.combinatorics.tensor_can import canonical_free
+    >>> gens = [[1, 0, 2, 3, 5, 4], [2, 3, 0, 1, 4, 5],[0, 1, 3, 2, 5, 4]]
+    >>> gens = [Permutation(h) for h in gens]
+    >>> base = [0, 2]
+    >>> g = Permutation([2, 1, 0, 3, 4, 5])
+    >>> canonical_free(base, gens, g, 4)
+    [0, 3, 1, 2, 5, 4]
+
+    Consider the product of Riemann tensors
+    ``T = R^{a}_{d0}^{d1,d2}*R_{d2,d1}^{d0,b}``
+    The order of the indices is ``[a, b, d0, -d0, d1, -d1, d2, -d2]``
+    The permutation corresponding to the tensor is
+    ``g = [0, 3, 4, 6, 7, 5, 2, 1, 8, 9]``
+
+    In particular ``a`` is position ``0``, ``b`` is in position ``9``.
+    Use the slot symmetries to get `T` is a form which is the minimal
+    in lexicographic order in the free indices ``a`` and ``b``, e.g.
+    ``-R^{a}_{d0}^{d1,d2}*R^{b,d0}_{d2,d1}`` corresponding to
+    ``[0, 3, 4, 6, 1, 2, 7, 5, 9, 8]``
+
+    >>> from sympy.combinatorics.tensor_can import riemann_bsgs, tensor_gens
+    >>> base, gens = riemann_bsgs
+    >>> size, sbase, sgens = tensor_gens(base, gens, [[], []], 0)
+    >>> g = Permutation([0, 3, 4, 6, 7, 5, 2, 1, 8, 9])
+    >>> canonical_free(sbase, [Permutation(h) for h in sgens], g, 2)
+    [0, 3, 4, 6, 1, 2, 7, 5, 9, 8]
+    """
+    g = g.array_form
+    size = len(g)
+    if not base:
+        return g[:]
+
+    transversals = get_transversals(base, gens)
+    for x in sorted(g[:-2]):
+        if x not in base:
+            base.append(x)
+    h = g
+    for i, transv in enumerate(transversals):
+        h_i = [size]*num_free
+        # find the element s in transversals[i] such that
+        # _af_rmul(h, s) has its free elements with the lowest position in h
+        s = None
+        for sk in transv.values():
+            h1 = _af_rmul(h, sk)
+            hi = [h1.index(ix) for ix in range(num_free)]
+            if hi < h_i:
+                h_i = hi
+                s = sk
+        if s:
+            h = _af_rmul(h, s)
+    return h
+
+
+def _get_map_slots(size, fixed_slots):
+    res = list(range(size))
+    pos = 0
+    for i in range(size):
+        if i in fixed_slots:
+            continue
+        res[i] = pos
+        pos += 1
+    return res
+
+
+def _lift_sgens(size, fixed_slots, free, s):
+    a = []
+    j = k = 0
+    fd = list(zip(fixed_slots, free))
+    fd = [y for x, y in sorted(fd)]
+    num_free = len(free)
+    for i in range(size):
+        if i in fixed_slots:
+            a.append(fd[k])
+            k += 1
+        else:
+            a.append(s[j] + num_free)
+            j += 1
+    return a
+
+
+def canonicalize(g, dummies, msym, *v):
+    """
+    canonicalize tensor formed by tensors
+
+    Parameters
+    ==========
+
+    g : permutation representing the tensor
+
+    dummies : list representing the dummy indices
+      it can be a list of dummy indices of the same type
+      or a list of lists of dummy indices, one list for each
+      type of index;
+      the dummy indices must come after the free indices,
+      and put in order contravariant, covariant
+      [d0, -d0, d1,-d1,...]
+
+    msym :  symmetry of the metric(s)
+        it can be an integer or a list;
+        in the first case it is the symmetry of the dummy index metric;
+        in the second case it is the list of the symmetries of the
+        index metric for each type
+
+    v : list, (base_i, gens_i, n_i, sym_i) for tensors of type `i`
+
+    base_i, gens_i : BSGS for tensors of this type.
+        The BSGS should have minimal base under lexicographic ordering;
+        if not, an attempt is made do get the minimal BSGS;
+        in case of failure,
+        canonicalize_naive is used, which is much slower.
+
+    n_i :    number of tensors of type `i`.
+
+    sym_i :  symmetry under exchange of component tensors of type `i`.
+
+        Both for msym and sym_i the cases are
+            * None  no symmetry
+            * 0     commuting
+            * 1     anticommuting
+
+    Returns
+    =======
+
+    0 if the tensor is zero, else return the array form of
+    the permutation representing the canonical form of the tensor.
+
+    Algorithm
+    =========
+
+    First one uses canonical_free to get the minimum tensor under
+    lexicographic order, using only the slot symmetries.
+    If the component tensors have not minimal BSGS, it is attempted
+    to find it; if the attempt fails canonicalize_naive
+    is used instead.
+
+    Compute the residual slot symmetry keeping fixed the free indices
+    using tensor_gens(base, gens, list_free_indices, sym).
+
+    Reduce the problem eliminating the free indices.
+
+    Then use double_coset_can_rep and lift back the result reintroducing
+    the free indices.
+
+    Examples
+    ========
+
+    one type of index with commuting metric;
+
+    `A_{a b}` and `B_{a b}` antisymmetric and commuting
+
+    `T = A_{d0 d1} * B^{d0}{}_{d2} * B^{d2 d1}`
+
+    `ord = [d0,-d0,d1,-d1,d2,-d2]` order of the indices
+
+    g = [1, 3, 0, 5, 4, 2, 6, 7]
+
+    `T_c = 0`
+
+    >>> from sympy.combinatorics.tensor_can import get_symmetric_group_sgs, canonicalize, bsgs_direct_product
+    >>> from sympy.combinatorics import Permutation
+    >>> base2a, gens2a = get_symmetric_group_sgs(2, 1)
+    >>> t0 = (base2a, gens2a, 1, 0)
+    >>> t1 = (base2a, gens2a, 2, 0)
+    >>> g = Permutation([1, 3, 0, 5, 4, 2, 6, 7])
+    >>> canonicalize(g, range(6), 0, t0, t1)
+    0
+
+    same as above, but with `B_{a b}` anticommuting
+
+    `T_c = -A^{d0 d1} * B_{d0}{}^{d2} * B_{d1 d2}`
+
+    can = [0,2,1,4,3,5,7,6]
+
+    >>> t1 = (base2a, gens2a, 2, 1)
+    >>> canonicalize(g, range(6), 0, t0, t1)
+    [0, 2, 1, 4, 3, 5, 7, 6]
+
+    two types of indices `[a,b,c,d,e,f]` and `[m,n]`, in this order,
+    both with commuting metric
+
+    `f^{a b c}` antisymmetric, commuting
+
+    `A_{m a}` no symmetry, commuting
+
+    `T = f^c{}_{d a} * f^f{}_{e b} * A_m{}^d * A^{m b} * A_n{}^a * A^{n e}`
+
+    ord = [c,f,a,-a,b,-b,d,-d,e,-e,m,-m,n,-n]
+
+    g = [0,7,3, 1,9,5, 11,6, 10,4, 13,2, 12,8, 14,15]
+
+    The canonical tensor is
+    `T_c = -f^{c a b} * f^{f d e} * A^m{}_a * A_{m d} * A^n{}_b * A_{n e}`
+
+    can = [0,2,4, 1,6,8, 10,3, 11,7, 12,5, 13,9, 15,14]
+
+    >>> base_f, gens_f = get_symmetric_group_sgs(3, 1)
+    >>> base1, gens1 = get_symmetric_group_sgs(1)
+    >>> base_A, gens_A = bsgs_direct_product(base1, gens1, base1, gens1)
+    >>> t0 = (base_f, gens_f, 2, 0)
+    >>> t1 = (base_A, gens_A, 4, 0)
+    >>> dummies = [range(2, 10), range(10, 14)]
+    >>> g = Permutation([0, 7, 3, 1, 9, 5, 11, 6, 10, 4, 13, 2, 12, 8, 14, 15])
+    >>> canonicalize(g, dummies, [0, 0], t0, t1)
+    [0, 2, 4, 1, 6, 8, 10, 3, 11, 7, 12, 5, 13, 9, 15, 14]
+    """
+    from sympy.combinatorics.testutil import canonicalize_naive
+    if not isinstance(msym, list):
+        if msym not in (0, 1, None):
+            raise ValueError('msym must be 0, 1 or None')
+        num_types = 1
+    else:
+        num_types = len(msym)
+        if not all(msymx in (0, 1, None) for msymx in msym):
+            raise ValueError('msym entries must be 0, 1 or None')
+        if len(dummies) != num_types:
+            raise ValueError(
+                'dummies and msym must have the same number of elements')
+    size = g.size
+    num_tensors = 0
+    v1 = []
+    for base_i, gens_i, n_i, sym_i in v:
+        # check that the BSGS is minimal;
+        # this property is used in double_coset_can_rep;
+        # if it is not minimal use canonicalize_naive
+        if not _is_minimal_bsgs(base_i, gens_i):
+            mbsgs = get_minimal_bsgs(base_i, gens_i)
+            if not mbsgs:
+                can = canonicalize_naive(g, dummies, msym, *v)
+                return can
+            base_i, gens_i = mbsgs
+        v1.append((base_i, gens_i, [[]] * n_i, sym_i))
+        num_tensors += n_i
+
+    if num_types == 1 and not isinstance(msym, list):
+        dummies = [dummies]
+        msym = [msym]
+    flat_dummies = []
+    for dumx in dummies:
+        flat_dummies.extend(dumx)
+
+    if flat_dummies and flat_dummies != list(range(flat_dummies[0], flat_dummies[-1] + 1)):
+        raise ValueError('dummies is not valid')
+
+    # slot symmetry of the tensor
+    size1, sbase, sgens = gens_products(*v1)
+    if size != size1:
+        raise ValueError(
+            'g has size %d, generators have size %d' % (size, size1))
+    free = [i for i in range(size - 2) if i not in flat_dummies]
+    num_free = len(free)
+
+    # g1 minimal tensor under slot symmetry
+    g1 = canonical_free(sbase, sgens, g, num_free)
+    if not flat_dummies:
+        return g1
+    # save the sign of g1
+    sign = 0 if g1[-1] == size - 1 else 1
+
+    # the free indices are kept fixed.
+    # Determine free_i, the list of slots of tensors which are fixed
+    # since they are occupied by free indices, which are fixed.
+    start = 0
+    for i, (base_i, gens_i, n_i, sym_i) in enumerate(v):
+        free_i = []
+        len_tens = gens_i[0].size - 2
+        # for each component tensor get a list od fixed islots
+        for j in range(n_i):
+            # get the elements corresponding to the component tensor
+            h = g1[start:(start + len_tens)]
+            fr = []
+            # get the positions of the fixed elements in h
+            for k in free:
+                if k in h:
+                    fr.append(h.index(k))
+            free_i.append(fr)
+            start += len_tens
+        v1[i] = (base_i, gens_i, free_i, sym_i)
+    # BSGS of the tensor with fixed free indices
+    # if tensor_gens fails in gens_product, use canonicalize_naive
+    size, sbase, sgens = gens_products(*v1)
+
+    # reduce the permutations getting rid of the free indices
+    pos_free = [g1.index(x) for x in range(num_free)]
+    size_red = size - num_free
+    g1_red = [x - num_free for x in g1 if x in flat_dummies]
+    if sign:
+        g1_red.extend([size_red - 1, size_red - 2])
+    else:
+        g1_red.extend([size_red - 2, size_red - 1])
+    map_slots = _get_map_slots(size, pos_free)
+    sbase_red = [map_slots[i] for i in sbase if i not in pos_free]
+    sgens_red = [_af_new([map_slots[i] for i in y._array_form if i not in pos_free]) for y in sgens]
+    dummies_red = [[x - num_free for x in y] for y in dummies]
+    transv_red = get_transversals(sbase_red, sgens_red)
+    g1_red = _af_new(g1_red)
+    g2 = double_coset_can_rep(
+        dummies_red, msym, sbase_red, sgens_red, transv_red, g1_red)
+    if g2 == 0:
+        return 0
+    # lift to the case with the free indices
+    g3 = _lift_sgens(size, pos_free, free, g2)
+    return g3
+
+
+def perm_af_direct_product(gens1, gens2, signed=True):
+    """
+    Direct products of the generators gens1 and gens2.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import perm_af_direct_product
+    >>> gens1 = [[1, 0, 2, 3], [0, 1, 3, 2]]
+    >>> gens2 = [[1, 0]]
+    >>> perm_af_direct_product(gens1, gens2, False)
+    [[1, 0, 2, 3, 4, 5], [0, 1, 3, 2, 4, 5], [0, 1, 2, 3, 5, 4]]
+    >>> gens1 = [[1, 0, 2, 3, 5, 4], [0, 1, 3, 2, 4, 5]]
+    >>> gens2 = [[1, 0, 2, 3]]
+    >>> perm_af_direct_product(gens1, gens2, True)
+    [[1, 0, 2, 3, 4, 5, 7, 6], [0, 1, 3, 2, 4, 5, 6, 7], [0, 1, 2, 3, 5, 4, 6, 7]]
+    """
+    gens1 = [list(x) for x in gens1]
+    gens2 = [list(x) for x in gens2]
+    s = 2 if signed else 0
+    n1 = len(gens1[0]) - s
+    n2 = len(gens2[0]) - s
+    start = list(range(n1))
+    end = list(range(n1, n1 + n2))
+    if signed:
+        gens1 = [gen[:-2] + end + [gen[-2] + n2, gen[-1] + n2]
+                 for gen in gens1]
+        gens2 = [start + [x + n1 for x in gen] for gen in gens2]
+    else:
+        gens1 = [gen + end for gen in gens1]
+        gens2 = [start + [x + n1 for x in gen] for gen in gens2]
+
+    res = gens1 + gens2
+
+    return res
+
+
+def bsgs_direct_product(base1, gens1, base2, gens2, signed=True):
+    """
+    Direct product of two BSGS.
+
+    Parameters
+    ==========
+
+    base1 : base of the first BSGS.
+
+    gens1 : strong generating sequence of the first BSGS.
+
+    base2, gens2 : similarly for the second BSGS.
+
+    signed : flag for signed permutations.
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import (get_symmetric_group_sgs, bsgs_direct_product)
+    >>> base1, gens1 = get_symmetric_group_sgs(1)
+    >>> base2, gens2 = get_symmetric_group_sgs(2)
+    >>> bsgs_direct_product(base1, gens1, base2, gens2)
+    ([1], [(4)(1 2)])
+    """
+    s = 2 if signed else 0
+    n1 = gens1[0].size - s
+    base = list(base1)
+    base += [x + n1 for x in base2]
+    gens1 = [h._array_form for h in gens1]
+    gens2 = [h._array_form for h in gens2]
+    gens = perm_af_direct_product(gens1, gens2, signed)
+    size = len(gens[0])
+    id_af = list(range(size))
+    gens = [h for h in gens if h != id_af]
+    if not gens:
+        gens = [id_af]
+    return base, [_af_new(h) for h in gens]
+
+
+def get_symmetric_group_sgs(n, antisym=False):
+    """
+    Return base, gens of the minimal BSGS for (anti)symmetric tensor
+
+    Parameters
+    ==========
+
+    n : rank of the tensor
+    antisym : bool
+        ``antisym = False`` symmetric tensor
+        ``antisym = True``  antisymmetric tensor
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import get_symmetric_group_sgs
+    >>> get_symmetric_group_sgs(3)
+    ([0, 1], [(4)(0 1), (4)(1 2)])
+    """
+    if n == 1:
+        return [], [_af_new(list(range(3)))]
+    gens = [Permutation(n - 1)(i, i + 1)._array_form for i in range(n - 1)]
+    if antisym == 0:
+        gens = [x + [n, n + 1] for x in gens]
+    else:
+        gens = [x + [n + 1, n] for x in gens]
+    base = list(range(n - 1))
+    return base, [_af_new(h) for h in gens]
+
+riemann_bsgs = [0, 2], [Permutation(0, 1)(4, 5), Permutation(2, 3)(4, 5),
+                        Permutation(5)(0, 2)(1, 3)]
+
+
+def get_transversals(base, gens):
+    """
+    Return transversals for the group with BSGS base, gens
+    """
+    if not base:
+        return []
+    stabs = _distribute_gens_by_base(base, gens)
+    orbits, transversals = _orbits_transversals_from_bsgs(base, stabs)
+    transversals = [{x: h._array_form for x, h in y.items()} for y in
+                    transversals]
+    return transversals
+
+
+def _is_minimal_bsgs(base, gens):
+    """
+    Check if the BSGS has minimal base under lexigographic order.
+
+    base, gens BSGS
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics import Permutation
+    >>> from sympy.combinatorics.tensor_can import riemann_bsgs, _is_minimal_bsgs
+    >>> _is_minimal_bsgs(*riemann_bsgs)
+    True
+    >>> riemann_bsgs1 = ([2, 0], ([Permutation(5)(0, 1)(4, 5), Permutation(5)(0, 2)(1, 3)]))
+    >>> _is_minimal_bsgs(*riemann_bsgs1)
+    False
+    """
+    base1 = []
+    sgs1 = gens[:]
+    size = gens[0].size
+    for i in range(size):
+        if not all(h._array_form[i] == i for h in sgs1):
+            base1.append(i)
+            sgs1 = [h for h in sgs1 if h._array_form[i] == i]
+    return base1 == base
+
+
+def get_minimal_bsgs(base, gens):
+    """
+    Compute a minimal GSGS
+
+    base, gens BSGS
+
+    If base, gens is a minimal BSGS return it; else return a minimal BSGS
+    if it fails in finding one, it returns None
+
+    TODO: use baseswap in the case in which if it fails in finding a
+    minimal BSGS
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics import Permutation
+    >>> from sympy.combinatorics.tensor_can import get_minimal_bsgs
+    >>> riemann_bsgs1 = ([2, 0], ([Permutation(5)(0, 1)(4, 5), Permutation(5)(0, 2)(1, 3)]))
+    >>> get_minimal_bsgs(*riemann_bsgs1)
+    ([0, 2], [(0 1)(4 5), (5)(0 2)(1 3), (2 3)(4 5)])
+    """
+    G = PermutationGroup(gens)
+    base, gens = G.schreier_sims_incremental()
+    if not _is_minimal_bsgs(base, gens):
+        return None
+    return base, gens
+
+
+def tensor_gens(base, gens, list_free_indices, sym=0):
+    """
+    Returns size, res_base, res_gens BSGS for n tensors of the
+    same type.
+
+    Explanation
+    ===========
+
+    base, gens BSGS for tensors of this type
+    list_free_indices  list of the slots occupied by fixed indices
+                       for each of the tensors
+
+    sym symmetry under commutation of two tensors
+    sym   None  no symmetry
+    sym   0     commuting
+    sym   1     anticommuting
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import tensor_gens, get_symmetric_group_sgs
+
+    two symmetric tensors with 3 indices without free indices
+
+    >>> base, gens = get_symmetric_group_sgs(3)
+    >>> tensor_gens(base, gens, [[], []])
+    (8, [0, 1, 3, 4], [(7)(0 1), (7)(1 2), (7)(3 4), (7)(4 5), (7)(0 3)(1 4)(2 5)])
+
+    two symmetric tensors with 3 indices with free indices in slot 1 and 0
+
+    >>> tensor_gens(base, gens, [[1], [0]])
+    (8, [0, 4], [(7)(0 2), (7)(4 5)])
+
+    four symmetric tensors with 3 indices, two of which with free indices
+
+    """
+    def _get_bsgs(G, base, gens, free_indices):
+        """
+        return the BSGS for G.pointwise_stabilizer(free_indices)
+        """
+        if not free_indices:
+            return base[:], gens[:]
+        else:
+            H = G.pointwise_stabilizer(free_indices)
+            base, sgs = H.schreier_sims_incremental()
+            return base, sgs
+
+    # if not base there is no slot symmetry for the component tensors
+    # if list_free_indices.count([]) < 2 there is no commutation symmetry
+    # so there is no resulting slot symmetry
+    if not base and list_free_indices.count([]) < 2:
+        n = len(list_free_indices)
+        size = gens[0].size
+        size = n * (size - 2) + 2
+        return size, [], [_af_new(list(range(size)))]
+
+    # if any(list_free_indices) one needs to compute the pointwise
+    # stabilizer, so G is needed
+    if any(list_free_indices):
+        G = PermutationGroup(gens)
+    else:
+        G = None
+
+    # no_free list of lists of indices for component tensors without fixed
+    # indices
+    no_free = []
+    size = gens[0].size
+    id_af = list(range(size))
+    num_indices = size - 2
+    if not list_free_indices[0]:
+        no_free.append(list(range(num_indices)))
+    res_base, res_gens = _get_bsgs(G, base, gens, list_free_indices[0])
+    for i in range(1, len(list_free_indices)):
+        base1, gens1 = _get_bsgs(G, base, gens, list_free_indices[i])
+        res_base, res_gens = bsgs_direct_product(res_base, res_gens,
+                                                 base1, gens1, 1)
+        if not list_free_indices[i]:
+            no_free.append(list(range(size - 2, size - 2 + num_indices)))
+        size += num_indices
+    nr = size - 2
+    res_gens = [h for h in res_gens if h._array_form != id_af]
+    # if sym there are no commuting tensors stop here
+    if sym is None or not no_free:
+        if not res_gens:
+            res_gens = [_af_new(id_af)]
+        return size, res_base, res_gens
+
+    # if the component tensors have moinimal BSGS, so is their direct
+    # product P; the slot symmetry group is S = P*C, where C is the group
+    # to (anti)commute the component tensors with no free indices
+    # a stabilizer has the property S_i = P_i*C_i;
+    # the BSGS of P*C has SGS_P + SGS_C and the base is
+    # the ordered union of the bases of P and C.
+    # If P has minimal BSGS, so has S with this base.
+    base_comm = []
+    for i in range(len(no_free) - 1):
+        ind1 = no_free[i]
+        ind2 = no_free[i + 1]
+        a = list(range(ind1[0]))
+        a.extend(ind2)
+        a.extend(ind1)
+        base_comm.append(ind1[0])
+        a.extend(list(range(ind2[-1] + 1, nr)))
+        if sym == 0:
+            a.extend([nr, nr + 1])
+        else:
+            a.extend([nr + 1, nr])
+        res_gens.append(_af_new(a))
+    res_base = list(res_base)
+    # each base is ordered; order the union of the two bases
+    for i in base_comm:
+        if i not in res_base:
+            res_base.append(i)
+    res_base.sort()
+    if not res_gens:
+        res_gens = [_af_new(id_af)]
+
+    return size, res_base, res_gens
+
+
+def gens_products(*v):
+    """
+    Returns size, res_base, res_gens BSGS for n tensors of different types.
+
+    Explanation
+    ===========
+
+    v is a sequence of (base_i, gens_i, free_i, sym_i)
+    where
+    base_i, gens_i  BSGS of tensor of type `i`
+    free_i          list of the fixed slots for each of the tensors
+                    of type `i`; if there are `n_i` tensors of type `i`
+                    and none of them have fixed slots, `free = [[]]*n_i`
+    sym   0 (1) if the tensors of type `i` (anti)commute among themselves
+
+    Examples
+    ========
+
+    >>> from sympy.combinatorics.tensor_can import get_symmetric_group_sgs, gens_products
+    >>> base, gens = get_symmetric_group_sgs(2)
+    >>> gens_products((base, gens, [[], []], 0))
+    (6, [0, 2], [(5)(0 1), (5)(2 3), (5)(0 2)(1 3)])
+    >>> gens_products((base, gens, [[1], []], 0))
+    (6, [2], [(5)(2 3)])
+    """
+    res_size, res_base, res_gens = tensor_gens(*v[0])
+    for i in range(1, len(v)):
+        size, base, gens = tensor_gens(*v[i])
+        res_base, res_gens = bsgs_direct_product(res_base, res_gens, base,
+                                                 gens, 1)
+    res_size = res_gens[0].size
+    id_af = list(range(res_size))
+    res_gens = [h for h in res_gens if h != id_af]
+    if not res_gens:
+        res_gens = [id_af]
+    return res_size, res_base, res_gens

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_coset_table.py

@@ -0,0 +1,825 @@
+from sympy.combinatorics.fp_groups import FpGroup
+from sympy.combinatorics.coset_table import (CosetTable,
+                    coset_enumeration_r, coset_enumeration_c)
+from sympy.combinatorics.coset_table import modified_coset_enumeration_r
+from sympy.combinatorics.free_groups import free_group
+
+from sympy.testing.pytest import slow
+
+"""
+References
+==========
+
+[1] Holt, D., Eick, B., O'Brien, E.
+"Handbook of Computational Group Theory"
+
+[2] John J. Cannon; Lucien A. Dimino; George Havas; Jane M. Watson
+Mathematics of Computation, Vol. 27, No. 123. (Jul., 1973), pp. 463-490.
+"Implementation and Analysis of the Todd-Coxeter Algorithm"
+
+"""
+
+def test_scan_1():
+    # Example 5.1 from [1]
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**3, y**3, x**-1*y**-1*x*y])
+    c = CosetTable(f, [x])
+
+    c.scan_and_fill(0, x)
+    assert c.table == [[0, 0, None, None]]
+    assert c.p == [0]
+    assert c.n == 1
+    assert c.omega == [0]
+
+    c.scan_and_fill(0, x**3)
+    assert c.table == [[0, 0, None, None]]
+    assert c.p == [0]
+    assert c.n == 1
+    assert c.omega == [0]
+
+    c.scan_and_fill(0, y**3)
+    assert c.table == [[0, 0, 1, 2], [None, None, 2, 0], [None, None, 0, 1]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(0, x**-1*y**-1*x*y)
+    assert c.table == [[0, 0, 1, 2], [None, None, 2, 0], [2, 2, 0, 1]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(1, x**3)
+    assert c.table == [[0, 0, 1, 2], [3, 4, 2, 0], [2, 2, 0, 1], \
+            [4, 1, None, None], [1, 3, None, None]]
+    assert c.p == [0, 1, 2, 3, 4]
+    assert c.n == 5
+    assert c.omega == [0, 1, 2, 3, 4]
+
+    c.scan_and_fill(1, y**3)
+    assert c.table == [[0, 0, 1, 2], [3, 4, 2, 0], [2, 2, 0, 1], \
+            [4, 1, None, None], [1, 3, None, None]]
+    assert c.p == [0, 1, 2, 3, 4]
+    assert c.n == 5
+    assert c.omega == [0, 1, 2, 3, 4]
+
+    c.scan_and_fill(1, x**-1*y**-1*x*y)
+    assert c.table == [[0, 0, 1, 2], [1, 1, 2, 0], [2, 2, 0, 1], \
+            [None, 1, None, None], [1, 3, None, None]]
+    assert c.p == [0, 1, 2, 1, 1]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    # Example 5.2 from [1]
+    f = FpGroup(F, [x**2, y**3, (x*y)**3])
+    c = CosetTable(f, [x*y])
+
+    c.scan_and_fill(0, x*y)
+    assert c.table == [[1, None, None, 1], [None, 0, 0, None]]
+    assert c.p == [0, 1]
+    assert c.n == 2
+    assert c.omega == [0, 1]
+
+    c.scan_and_fill(0, x**2)
+    assert c.table == [[1, 1, None, 1], [0, 0, 0, None]]
+    assert c.p == [0, 1]
+    assert c.n == 2
+    assert c.omega == [0, 1]
+
+    c.scan_and_fill(0, y**3)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [None, None, 1, 0]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(0, (x*y)**3)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [None, None, 1, 0]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(1, x**2)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [None, None, 1, 0]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(1, y**3)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [None, None, 1, 0]]
+    assert c.p == [0, 1, 2]
+    assert c.n == 3
+    assert c.omega == [0, 1, 2]
+
+    c.scan_and_fill(1, (x*y)**3)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [3, 4, 1, 0], [None, 2, 4, None], [2, None, None, 3]]
+    assert c.p == [0, 1, 2, 3, 4]
+    assert c.n == 5
+    assert c.omega == [0, 1, 2, 3, 4]
+
+    c.scan_and_fill(2, x**2)
+    assert c.table == [[1, 1, 2, 1], [0, 0, 0, 2], [3, 3, 1, 0], [2, 2, 3, 3], [2, None, None, 3]]
+    assert c.p == [0, 1, 2, 3, 3]
+    assert c.n == 4
+    assert c.omega == [0, 1, 2, 3]
+
+
+@slow
+def test_coset_enumeration():
+    # this test function contains the combined tests for the two strategies
+    # i.e. HLT and Felsch strategies.
+
+    # Example 5.1 from [1]
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**3, y**3, x**-1*y**-1*x*y])
+    C_r = coset_enumeration_r(f, [x])
+    C_r.compress(); C_r.standardize()
+    C_c = coset_enumeration_c(f, [x])
+    C_c.compress(); C_c.standardize()
+    table1 = [[0, 0, 1, 2], [1, 1, 2, 0], [2, 2, 0, 1]]
+    assert C_r.table == table1
+    assert C_c.table == table1
+
+    # E1 from [2] Pg. 474
+    F, r, s, t = free_group("r, s, t")
+    E1 = FpGroup(F, [t**-1*r*t*r**-2, r**-1*s*r*s**-2, s**-1*t*s*t**-2])
+    C_r = coset_enumeration_r(E1, [])
+    C_r.compress()
+    C_c = coset_enumeration_c(E1, [])
+    C_c.compress()
+    table2 = [[0, 0, 0, 0, 0, 0]]
+    assert C_r.table == table2
+    # test for issue #11449
+    assert C_c.table == table2
+
+    # Cox group from [2] Pg. 474
+    F, a, b = free_group("a, b")
+    Cox = FpGroup(F, [a**6, b**6, (a*b)**2, (a**2*b**2)**2, (a**3*b**3)**5])
+    C_r = coset_enumeration_r(Cox, [a])
+    C_r.compress(); C_r.standardize()
+    C_c = coset_enumeration_c(Cox, [a])
+    C_c.compress(); C_c.standardize()
+    table3 = [[0, 0, 1, 2],
+             [2, 3, 4, 0],
+             [5, 1, 0, 6],
+             [1, 7, 8, 9],
+             [9, 10, 11, 1],
+             [12, 2, 9, 13],
+             [14, 9, 2, 11],
+             [3, 12, 15, 16],
+             [16, 17, 18, 3],
+             [6, 4, 3, 5],
+             [4, 19, 20, 21],
+             [21, 22, 6, 4],
+             [7, 5, 23, 24],
+             [25, 23, 5, 18],
+             [19, 6, 22, 26],
+             [24, 27, 28, 7],
+             [29, 8, 7, 30],
+             [8, 31, 32, 33],
+             [33, 34, 13, 8],
+             [10, 14, 35, 35],
+             [35, 36, 37, 10],
+             [30, 11, 10, 29],
+             [11, 38, 39, 14],
+             [13, 39, 38, 12],
+             [40, 15, 12, 41],
+             [42, 13, 34, 43],
+             [44, 35, 14, 45],
+             [15, 46, 47, 34],
+             [34, 48, 49, 15],
+             [50, 16, 21, 51],
+             [52, 21, 16, 49],
+             [17, 50, 53, 54],
+             [54, 55, 56, 17],
+             [41, 18, 17, 40],
+             [18, 28, 27, 25],
+             [26, 20, 19, 19],
+             [20, 57, 58, 59],
+             [59, 60, 51, 20],
+             [22, 52, 61, 23],
+             [23, 62, 63, 22],
+             [64, 24, 33, 65],
+             [48, 33, 24, 61],
+             [62, 25, 54, 66],
+             [67, 54, 25, 68],
+             [57, 26, 59, 69],
+             [70, 59, 26, 63],
+             [27, 64, 71, 72],
+             [72, 73, 68, 27],
+             [28, 41, 74, 75],
+             [75, 76, 30, 28],
+             [31, 29, 77, 78],
+             [79, 77, 29, 37],
+             [38, 30, 76, 80],
+             [78, 81, 82, 31],
+             [43, 32, 31, 42],
+             [32, 83, 84, 85],
+             [85, 86, 65, 32],
+             [36, 44, 87, 88],
+             [88, 89, 90, 36],
+             [45, 37, 36, 44],
+             [37, 82, 81, 79],
+             [80, 74, 41, 38],
+             [39, 42, 91, 92],
+             [92, 93, 45, 39],
+             [46, 40, 94, 95],
+             [96, 94, 40, 56],
+             [97, 91, 42, 82],
+             [83, 43, 98, 99],
+             [100, 98, 43, 47],
+             [101, 87, 44, 90],
+             [82, 45, 93, 97],
+             [95, 102, 103, 46],
+             [104, 47, 46, 105],
+             [47, 106, 107, 100],
+             [61, 108, 109, 48],
+             [105, 49, 48, 104],
+             [49, 110, 111, 52],
+             [51, 111, 110, 50],
+             [112, 53, 50, 113],
+             [114, 51, 60, 115],
+             [116, 61, 52, 117],
+             [53, 118, 119, 60],
+             [60, 70, 66, 53],
+             [55, 67, 120, 121],
+             [121, 122, 123, 55],
+             [113, 56, 55, 112],
+             [56, 103, 102, 96],
+             [69, 124, 125, 57],
+             [115, 58, 57, 114],
+             [58, 126, 127, 128],
+             [128, 128, 69, 58],
+             [66, 129, 130, 62],
+             [117, 63, 62, 116],
+             [63, 125, 124, 70],
+             [65, 109, 108, 64],
+             [131, 71, 64, 132],
+             [133, 65, 86, 134],
+             [135, 66, 70, 136],
+             [68, 130, 129, 67],
+             [137, 120, 67, 138],
+             [132, 68, 73, 131],
+             [139, 69, 128, 140],
+             [71, 141, 142, 86],
+             [86, 143, 144, 71],
+             [145, 72, 75, 146],
+             [147, 75, 72, 144],
+             [73, 145, 148, 120],
+             [120, 149, 150, 73],
+             [74, 151, 152, 94],
+             [94, 153, 146, 74],
+             [76, 147, 154, 77],
+             [77, 155, 156, 76],
+             [157, 78, 85, 158],
+             [143, 85, 78, 154],
+             [155, 79, 88, 159],
+             [160, 88, 79, 161],
+             [151, 80, 92, 162],
+             [163, 92, 80, 156],
+             [81, 157, 164, 165],
+             [165, 166, 161, 81],
+             [99, 107, 106, 83],
+             [134, 84, 83, 133],
+             [84, 167, 168, 169],
+             [169, 170, 158, 84],
+             [87, 171, 172, 93],
+             [93, 163, 159, 87],
+             [89, 160, 173, 174],
+             [174, 175, 176, 89],
+             [90, 90, 89, 101],
+             [91, 177, 178, 98],
+             [98, 179, 162, 91],
+             [180, 95, 100, 181],
+             [179, 100, 95, 152],
+             [153, 96, 121, 148],
+             [182, 121, 96, 183],
+             [177, 97, 165, 184],
+             [185, 165, 97, 172],
+             [186, 99, 169, 187],
+             [188, 169, 99, 178],
+             [171, 101, 174, 189],
+             [190, 174, 101, 176],
+             [102, 180, 191, 192],
+             [192, 193, 183, 102],
+             [103, 113, 194, 195],
+             [195, 196, 105, 103],
+             [106, 104, 197, 198],
+             [199, 197, 104, 109],
+             [110, 105, 196, 200],
+             [198, 201, 133, 106],
+             [107, 186, 202, 203],
+             [203, 204, 181, 107],
+             [108, 116, 205, 206],
+             [206, 207, 132, 108],
+             [109, 133, 201, 199],
+             [200, 194, 113, 110],
+             [111, 114, 208, 209],
+             [209, 210, 117, 111],
+             [118, 112, 211, 212],
+             [213, 211, 112, 123],
+             [214, 208, 114, 125],
+             [126, 115, 215, 216],
+             [217, 215, 115, 119],
+             [218, 205, 116, 130],
+             [125, 117, 210, 214],
+             [212, 219, 220, 118],
+             [136, 119, 118, 135],
+             [119, 221, 222, 217],
+             [122, 182, 223, 224],
+             [224, 225, 226, 122],
+             [138, 123, 122, 137],
+             [123, 220, 219, 213],
+             [124, 139, 227, 228],
+             [228, 229, 136, 124],
+             [216, 222, 221, 126],
+             [140, 127, 126, 139],
+             [127, 230, 231, 232],
+             [232, 233, 140, 127],
+             [129, 135, 234, 235],
+             [235, 236, 138, 129],
+             [130, 132, 207, 218],
+             [141, 131, 237, 238],
+             [239, 237, 131, 150],
+             [167, 134, 240, 241],
+             [242, 240, 134, 142],
+             [243, 234, 135, 220],
+             [221, 136, 229, 244],
+             [149, 137, 245, 246],
+             [247, 245, 137, 226],
+             [220, 138, 236, 243],
+             [244, 227, 139, 221],
+             [230, 140, 233, 248],
+             [238, 249, 250, 141],
+             [251, 142, 141, 252],
+             [142, 253, 254, 242],
+             [154, 255, 256, 143],
+             [252, 144, 143, 251],
+             [144, 257, 258, 147],
+             [146, 258, 257, 145],
+             [259, 148, 145, 260],
+             [261, 146, 153, 262],
+             [263, 154, 147, 264],
+             [148, 265, 266, 153],
+             [246, 267, 268, 149],
+             [260, 150, 149, 259],
+             [150, 250, 249, 239],
+             [162, 269, 270, 151],
+             [262, 152, 151, 261],
+             [152, 271, 272, 179],
+             [159, 273, 274, 155],
+             [264, 156, 155, 263],
+             [156, 270, 269, 163],
+             [158, 256, 255, 157],
+             [275, 164, 157, 276],
+             [277, 158, 170, 278],
+             [279, 159, 163, 280],
+             [161, 274, 273, 160],
+             [281, 173, 160, 282],
+             [276, 161, 166, 275],
+             [283, 162, 179, 284],
+             [164, 285, 286, 170],
+             [170, 188, 184, 164],
+             [166, 185, 189, 173],
+             [173, 287, 288, 166],
+             [241, 254, 253, 167],
+             [278, 168, 167, 277],
+             [168, 289, 290, 291],
+             [291, 292, 187, 168],
+             [189, 293, 294, 171],
+             [280, 172, 171, 279],
+             [172, 295, 296, 185],
+             [175, 190, 297, 297],
+             [297, 298, 299, 175],
+             [282, 176, 175, 281],
+             [176, 294, 293, 190],
+             [184, 296, 295, 177],
+             [284, 178, 177, 283],
+             [178, 300, 301, 188],
+             [181, 272, 271, 180],
+             [302, 191, 180, 303],
+             [304, 181, 204, 305],
+             [183, 266, 265, 182],
+             [306, 223, 182, 307],
+             [303, 183, 193, 302],
+             [308, 184, 188, 309],
+             [310, 189, 185, 311],
+             [187, 301, 300, 186],
+             [305, 202, 186, 304],
+             [312, 187, 292, 313],
+             [314, 297, 190, 315],
+             [191, 316, 317, 204],
+             [204, 318, 319, 191],
+             [320, 192, 195, 321],
+             [322, 195, 192, 319],
+             [193, 320, 323, 223],
+             [223, 324, 325, 193],
+             [194, 326, 327, 211],
+             [211, 328, 321, 194],
+             [196, 322, 329, 197],
+             [197, 330, 331, 196],
+             [332, 198, 203, 333],
+             [318, 203, 198, 329],
+             [330, 199, 206, 334],
+             [335, 206, 199, 336],
+             [326, 200, 209, 337],
+             [338, 209, 200, 331],
+             [201, 332, 339, 240],
+             [240, 340, 336, 201],
+             [202, 341, 342, 292],
+             [292, 343, 333, 202],
+             [205, 344, 345, 210],
+             [210, 338, 334, 205],
+             [207, 335, 346, 237],
+             [237, 347, 348, 207],
+             [208, 349, 350, 215],
+             [215, 351, 337, 208],
+             [352, 212, 217, 353],
+             [351, 217, 212, 327],
+             [328, 213, 224, 323],
+             [354, 224, 213, 355],
+             [349, 214, 228, 356],
+             [357, 228, 214, 345],
+             [358, 216, 232, 359],
+             [360, 232, 216, 350],
+             [344, 218, 235, 361],
+             [362, 235, 218, 348],
+             [219, 352, 363, 364],
+             [364, 365, 355, 219],
+             [222, 358, 366, 367],
+             [367, 368, 353, 222],
+             [225, 354, 369, 370],
+             [370, 371, 372, 225],
+             [307, 226, 225, 306],
+             [226, 268, 267, 247],
+             [227, 373, 374, 233],
+             [233, 360, 356, 227],
+             [229, 357, 361, 234],
+             [234, 375, 376, 229],
+             [248, 231, 230, 230],
+             [231, 377, 378, 379],
+             [379, 380, 359, 231],
+             [236, 362, 381, 245],
+             [245, 382, 383, 236],
+             [384, 238, 242, 385],
+             [340, 242, 238, 346],
+             [347, 239, 246, 381],
+             [386, 246, 239, 387],
+             [388, 241, 291, 389],
+             [343, 291, 241, 339],
+             [375, 243, 364, 390],
+             [391, 364, 243, 383],
+             [373, 244, 367, 392],
+             [393, 367, 244, 376],
+             [382, 247, 370, 394],
+             [395, 370, 247, 396],
+             [377, 248, 379, 397],
+             [398, 379, 248, 374],
+             [249, 384, 399, 400],
+             [400, 401, 387, 249],
+             [250, 260, 402, 403],
+             [403, 404, 252, 250],
+             [253, 251, 405, 406],
+             [407, 405, 251, 256],
+             [257, 252, 404, 408],
+             [406, 409, 277, 253],
+             [254, 388, 410, 411],
+             [411, 412, 385, 254],
+             [255, 263, 413, 414],
+             [414, 415, 276, 255],
+             [256, 277, 409, 407],
+             [408, 402, 260, 257],
+             [258, 261, 416, 417],
+             [417, 418, 264, 258],
+             [265, 259, 419, 420],
+             [421, 419, 259, 268],
+             [422, 416, 261, 270],
+             [271, 262, 423, 424],
+             [425, 423, 262, 266],
+             [426, 413, 263, 274],
+             [270, 264, 418, 422],
+             [420, 427, 307, 265],
+             [266, 303, 428, 425],
+             [267, 386, 429, 430],
+             [430, 431, 396, 267],
+             [268, 307, 427, 421],
+             [269, 283, 432, 433],
+             [433, 434, 280, 269],
+             [424, 428, 303, 271],
+             [272, 304, 435, 436],
+             [436, 437, 284, 272],
+             [273, 279, 438, 439],
+             [439, 440, 282, 273],
+             [274, 276, 415, 426],
+             [285, 275, 441, 442],
+             [443, 441, 275, 288],
+             [289, 278, 444, 445],
+             [446, 444, 278, 286],
+             [447, 438, 279, 294],
+             [295, 280, 434, 448],
+             [287, 281, 449, 450],
+             [451, 449, 281, 299],
+             [294, 282, 440, 447],
+             [448, 432, 283, 295],
+             [300, 284, 437, 452],
+             [442, 453, 454, 285],
+             [309, 286, 285, 308],
+             [286, 455, 456, 446],
+             [450, 457, 458, 287],
+             [311, 288, 287, 310],
+             [288, 454, 453, 443],
+             [445, 456, 455, 289],
+             [313, 290, 289, 312],
+             [290, 459, 460, 461],
+             [461, 462, 389, 290],
+             [293, 310, 463, 464],
+             [464, 465, 315, 293],
+             [296, 308, 466, 467],
+             [467, 468, 311, 296],
+             [298, 314, 469, 470],
+             [470, 471, 472, 298],
+             [315, 299, 298, 314],
+             [299, 458, 457, 451],
+             [452, 435, 304, 300],
+             [301, 312, 473, 474],
+             [474, 475, 309, 301],
+             [316, 302, 476, 477],
+             [478, 476, 302, 325],
+             [341, 305, 479, 480],
+             [481, 479, 305, 317],
+             [324, 306, 482, 483],
+             [484, 482, 306, 372],
+             [485, 466, 308, 454],
+             [455, 309, 475, 486],
+             [487, 463, 310, 458],
+             [454, 311, 468, 485],
+             [486, 473, 312, 455],
+             [459, 313, 488, 489],
+             [490, 488, 313, 342],
+             [491, 469, 314, 472],
+             [458, 315, 465, 487],
+             [477, 492, 485, 316],
+             [463, 317, 316, 468],
+             [317, 487, 493, 481],
+             [329, 447, 464, 318],
+             [468, 319, 318, 463],
+             [319, 467, 448, 322],
+             [321, 448, 467, 320],
+             [475, 323, 320, 466],
+             [432, 321, 328, 437],
+             [438, 329, 322, 434],
+             [323, 474, 452, 328],
+             [483, 494, 486, 324],
+             [466, 325, 324, 475],
+             [325, 485, 492, 478],
+             [337, 422, 433, 326],
+             [437, 327, 326, 432],
+             [327, 436, 424, 351],
+             [334, 426, 439, 330],
+             [434, 331, 330, 438],
+             [331, 433, 422, 338],
+             [333, 464, 447, 332],
+             [449, 339, 332, 440],
+             [465, 333, 343, 469],
+             [413, 334, 338, 418],
+             [336, 439, 426, 335],
+             [441, 346, 335, 415],
+             [440, 336, 340, 449],
+             [416, 337, 351, 423],
+             [339, 451, 470, 343],
+             [346, 443, 450, 340],
+             [480, 493, 487, 341],
+             [469, 342, 341, 465],
+             [342, 491, 495, 490],
+             [361, 407, 414, 344],
+             [418, 345, 344, 413],
+             [345, 417, 408, 357],
+             [381, 446, 442, 347],
+             [415, 348, 347, 441],
+             [348, 414, 407, 362],
+             [356, 408, 417, 349],
+             [423, 350, 349, 416],
+             [350, 425, 420, 360],
+             [353, 424, 436, 352],
+             [479, 363, 352, 435],
+             [428, 353, 368, 476],
+             [355, 452, 474, 354],
+             [488, 369, 354, 473],
+             [435, 355, 365, 479],
+             [402, 356, 360, 419],
+             [405, 361, 357, 404],
+             [359, 420, 425, 358],
+             [476, 366, 358, 428],
+             [427, 359, 380, 482],
+             [444, 381, 362, 409],
+             [363, 481, 477, 368],
+             [368, 393, 390, 363],
+             [365, 391, 394, 369],
+             [369, 490, 480, 365],
+             [366, 478, 483, 380],
+             [380, 398, 392, 366],
+             [371, 395, 496, 497],
+             [497, 498, 489, 371],
+             [473, 372, 371, 488],
+             [372, 486, 494, 484],
+             [392, 400, 403, 373],
+             [419, 374, 373, 402],
+             [374, 421, 430, 398],
+             [390, 411, 406, 375],
+             [404, 376, 375, 405],
+             [376, 403, 400, 393],
+             [397, 430, 421, 377],
+             [482, 378, 377, 427],
+             [378, 484, 497, 499],
+             [499, 499, 397, 378],
+             [394, 461, 445, 382],
+             [409, 383, 382, 444],
+             [383, 406, 411, 391],
+             [385, 450, 443, 384],
+             [492, 399, 384, 453],
+             [457, 385, 412, 493],
+             [387, 442, 446, 386],
+             [494, 429, 386, 456],
+             [453, 387, 401, 492],
+             [389, 470, 451, 388],
+             [493, 410, 388, 457],
+             [471, 389, 462, 495],
+             [412, 390, 393, 399],
+             [462, 394, 391, 410],
+             [401, 392, 398, 429],
+             [396, 445, 461, 395],
+             [498, 496, 395, 460],
+             [456, 396, 431, 494],
+             [431, 397, 499, 496],
+             [399, 477, 481, 412],
+             [429, 483, 478, 401],
+             [410, 480, 490, 462],
+             [496, 497, 484, 431],
+             [489, 495, 491, 459],
+             [495, 460, 459, 471],
+             [460, 489, 498, 498],
+             [472, 472, 471, 491]]
+
+    assert C_r.table == table3
+    assert C_c.table == table3
+
+    # Group denoted by B2,4 from [2] Pg. 474
+    F, a, b = free_group("a, b")
+    B_2_4 = FpGroup(F, [a**4, b**4, (a*b)**4, (a**-1*b)**4, (a**2*b)**4, \
+            (a*b**2)**4, (a**2*b**2)**4, (a**-1*b*a*b)**4, (a*b**-1*a*b)**4])
+    C_r = coset_enumeration_r(B_2_4, [a])
+    C_c = coset_enumeration_c(B_2_4, [a])
+    index_r = 0
+    for i in range(len(C_r.p)):
+        if C_r.p[i] == i:
+            index_r += 1
+    assert index_r == 1024
+
+    index_c = 0
+    for i in range(len(C_c.p)):
+        if C_c.p[i] == i:
+            index_c += 1
+    assert index_c == 1024
+
+    # trivial Macdonald group G(2,2) from [2] Pg. 480
+    M = FpGroup(F, [b**-1*a**-1*b*a*b**-1*a*b*a**-2, a**-1*b**-1*a*b*a**-1*b*a*b**-2])
+    C_r = coset_enumeration_r(M, [a])
+    C_r.compress(); C_r.standardize()
+    C_c = coset_enumeration_c(M, [a])
+    C_c.compress(); C_c.standardize()
+    table4 = [[0, 0, 0, 0]]
+    assert C_r.table == table4
+    assert C_c.table == table4
+
+
+def test_look_ahead():
+    # Section 3.2 [Test Example] Example (d) from [2]
+    F, a, b, c = free_group("a, b, c")
+    f = FpGroup(F, [a**11, b**5, c**4, (a*c)**3, b**2*c**-1*b**-1*c, a**4*b**-1*a**-1*b])
+    H = [c, b, c**2]
+    table0 = [[1, 2, 0, 0, 0, 0],
+              [3, 0, 4, 5, 6, 7],
+              [0, 8, 9, 10, 11, 12],
+              [5, 1, 10, 13, 14, 15],
+              [16, 5, 16, 1, 17, 18],
+              [4, 3, 1, 8, 19, 20],
+              [12, 21, 22, 23, 24, 1],
+              [25, 26, 27, 28, 1, 24],
+              [2, 10, 5, 16, 22, 28],
+              [10, 13, 13, 2, 29, 30]]
+    CosetTable.max_stack_size = 10
+    C_c = coset_enumeration_c(f, H)
+    C_c.compress(); C_c.standardize()
+    assert C_c.table[: 10] == table0
+
+def test_modified_methods():
+    '''
+    Tests for modified coset table methods.
+    Example 5.7 from [1] Holt, D., Eick, B., O'Brien
+    "Handbook of Computational Group Theory".
+
+    '''
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**3, y**5, (x*y)**2])
+    H = [x*y, x**-1*y**-1*x*y*x]
+    C = CosetTable(f, H)
+    C.modified_define(0, x)
+    identity = C._grp.identity
+    a_0 = C._grp.generators[0]
+    a_1 = C._grp.generators[1]
+
+    assert C.P == [[identity, None, None, None],
+                    [None, identity, None, None]]
+    assert C.table == [[1, None, None, None],
+                        [None, 0, None, None]]
+
+    C.modified_define(1, x)
+    assert C.table == [[1, None, None, None],
+                        [2, 0, None, None],
+                        [None, 1, None, None]]
+    assert C.P == [[identity, None, None, None],
+                    [identity, identity, None, None],
+                    [None, identity, None, None]]
+
+    C.modified_scan(0, x**3, C._grp.identity, fill=False)
+    assert C.P == [[identity, identity, None, None],
+                     [identity, identity, None, None],
+                     [identity, identity, None, None]]
+    assert C.table == [[1, 2, None, None],
+                        [2, 0, None, None],
+                        [0, 1, None, None]]
+
+    C.modified_scan(0, x*y, C._grp.generators[0], fill=False)
+    assert C.P == [[identity, identity, None, a_0**-1],
+                    [identity, identity, a_0, None],
+                    [identity, identity, None, None]]
+    assert C.table == [[1, 2, None, 1],
+                        [2, 0, 0, None],
+                        [0, 1, None, None]]
+
+    C.modified_define(2, y**-1)
+    assert C.table == [[1, 2, None, 1],
+                        [2, 0, 0, None],
+                        [0, 1, None, 3],
+                        [None, None, 2, None]]
+    assert C.P == [[identity, identity, None, a_0**-1],
+                    [identity, identity, a_0, None],
+                    [identity, identity, None, identity],
+                    [None, None, identity, None]]
+
+    C.modified_scan(0, x**-1*y**-1*x*y*x, C._grp.generators[1])
+    assert C.table == [[1, 2, None, 1],
+                        [2, 0, 0, None],
+                        [0, 1, None, 3],
+                        [3, 3, 2, None]]
+    assert C.P == [[identity, identity, None, a_0**-1],
+                    [identity, identity, a_0, None],
+                    [identity, identity, None, identity],
+                    [a_1, a_1**-1, identity, None]]
+
+    C.modified_scan(2, (x*y)**2, C._grp.identity)
+    assert C.table == [[1, 2, 3, 1],
+                        [2, 0, 0, None],
+                        [0, 1, None, 3],
+                        [3, 3, 2, 0]]
+    assert C.P == [[identity, identity, a_1**-1, a_0**-1],
+                    [identity, identity, a_0, None],
+                    [identity, identity, None, identity],
+                    [a_1, a_1**-1, identity, a_1]]
+
+    C.modified_define(2, y)
+    assert C.table == [[1, 2, 3, 1],
+                        [2, 0, 0, None],
+                        [0, 1, 4, 3],
+                        [3, 3, 2, 0],
+                        [None, None, None, 2]]
+    assert C.P == [[identity, identity, a_1**-1, a_0**-1],
+                    [identity, identity, a_0, None],
+                    [identity, identity, identity, identity],
+                    [a_1, a_1**-1, identity, a_1],
+                    [None, None, None, identity]]
+
+    C.modified_scan(0, y**5, C._grp.identity)
+    assert C.table == [[1, 2, 3, 1], [2, 0, 0, 4], [0, 1, 4, 3], [3, 3, 2, 0], [None, None, 1, 2]]
+    assert C.P == [[identity, identity, a_1**-1, a_0**-1],
+                    [identity, identity, a_0, a_0*a_1**-1],
+                    [identity, identity, identity, identity],
+                    [a_1, a_1**-1, identity, a_1],
+                    [None, None, a_1*a_0**-1, identity]]
+
+    C.modified_scan(1, (x*y)**2, C._grp.identity)
+    assert C.table == [[1, 2, 3, 1],
+                        [2, 0, 0, 4],
+                        [0, 1, 4, 3],
+                        [3, 3, 2, 0],
+                        [4, 4, 1, 2]]
+    assert C.P == [[identity, identity, a_1**-1, a_0**-1],
+                    [identity, identity, a_0, a_0*a_1**-1],
+                    [identity, identity, identity, identity],
+                    [a_1, a_1**-1, identity, a_1],
+                    [a_0*a_1**-1, a_1*a_0**-1, a_1*a_0**-1, identity]]
+
+    # Modified coset enumeration test
+    f = FpGroup(F, [x**3, y**3, x**-1*y**-1*x*y])
+    C = coset_enumeration_r(f, [x])
+    C_m = modified_coset_enumeration_r(f, [x])
+    assert C_m.table == C.table

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_fp_groups.py

@@ -0,0 +1,252 @@
+from sympy.core.singleton import S
+from sympy.combinatorics.fp_groups import (FpGroup, low_index_subgroups,
+                                   reidemeister_presentation, FpSubgroup,
+                                           simplify_presentation)
+from sympy.combinatorics.free_groups import (free_group, FreeGroup)
+
+from sympy.testing.pytest import slow
+
+"""
+References
+==========
+
+[1] Holt, D., Eick, B., O'Brien, E.
+"Handbook of Computational Group Theory"
+
+[2] John J. Cannon; Lucien A. Dimino; George Havas; Jane M. Watson
+Mathematics of Computation, Vol. 27, No. 123. (Jul., 1973), pp. 463-490.
+"Implementation and Analysis of the Todd-Coxeter Algorithm"
+
+[3] PROC. SECOND  INTERNAT. CONF. THEORY OF GROUPS, CANBERRA 1973,
+pp. 347-356. "A Reidemeister-Schreier program" by George Havas.
+http://staff.itee.uq.edu.au/havas/1973cdhw.pdf
+
+"""
+
+def test_low_index_subgroups():
+    F, x, y = free_group("x, y")
+
+    # Example 5.10 from [1] Pg. 194
+    f = FpGroup(F, [x**2, y**3, (x*y)**4])
+    L = low_index_subgroups(f, 4)
+    t1 = [[[0, 0, 0, 0]],
+          [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 3, 3]],
+          [[0, 0, 1, 2], [2, 2, 2, 0], [1, 1, 0, 1]],
+          [[1, 1, 0, 0], [0, 0, 1, 1]]]
+    for i in range(len(t1)):
+        assert L[i].table == t1[i]
+
+    f = FpGroup(F, [x**2, y**3, (x*y)**7])
+    L = low_index_subgroups(f, 15)
+    t2 = [[[0, 0, 0, 0]],
+           [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5],
+            [4, 4, 5, 3], [6, 6, 3, 4], [5, 5, 6, 6]],
+           [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5],
+            [6, 6, 5, 3], [5, 5, 3, 4], [4, 4, 6, 6]],
+           [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5],
+            [6, 6, 5, 3], [7, 7, 3, 4], [4, 4, 8, 9], [5, 5, 10, 11],
+            [11, 11, 9, 6], [9, 9, 6, 8], [12, 12, 11, 7], [8, 8, 7, 10],
+            [10, 10, 13, 14], [14, 14, 14, 12], [13, 13, 12, 13]],
+           [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5],
+            [6, 6, 5, 3], [7, 7, 3, 4], [4, 4, 8, 9], [5, 5, 10, 11],
+            [11, 11, 9, 6], [12, 12, 6, 8], [10, 10, 11, 7], [8, 8, 7, 10],
+            [9, 9, 13, 14], [14, 14, 14, 12], [13, 13, 12, 13]],
+           [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5],
+            [6, 6, 5, 3], [7, 7, 3, 4], [4, 4, 8, 9], [5, 5, 10, 11],
+            [11, 11, 9, 6], [12, 12, 6, 8], [13, 13, 11, 7], [8, 8, 7, 10],
+            [9, 9, 12, 12], [10, 10, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 3, 3], [2, 2, 5, 6]
+            , [7, 7, 6, 4], [8, 8, 4, 5], [5, 5, 8, 9], [6, 6, 9, 7],
+            [10, 10, 7, 8], [9, 9, 11, 12], [11, 11, 12, 10], [13, 13, 10, 11],
+            [12, 12, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 3, 3], [2, 2, 5, 6]
+            , [7, 7, 6, 4], [8, 8, 4, 5], [5, 5, 8, 9], [6, 6, 9, 7],
+            [10, 10, 7, 8], [9, 9, 11, 12], [13, 13, 12, 10], [12, 12, 10, 11],
+            [11, 11, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 4, 4]
+            , [7, 7, 6, 3], [8, 8, 3, 5], [5, 5, 8, 9], [6, 6, 9, 7],
+            [10, 10, 7, 8], [9, 9, 11, 12], [13, 13, 12, 10], [12, 12, 10, 11],
+            [11, 11, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [5, 5, 6, 3], [9, 9, 3, 5], [10, 10, 8, 4], [8, 8, 4, 7],
+            [6, 6, 10, 11], [7, 7, 11, 9], [12, 12, 9, 10], [11, 11, 13, 14],
+            [14, 14, 14, 12], [13, 13, 12, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [6, 6, 6, 3], [5, 5, 3, 5], [8, 8, 8, 4], [7, 7, 4, 7]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [9, 9, 6, 3], [6, 6, 3, 5], [10, 10, 8, 4], [11, 11, 4, 7],
+            [5, 5, 10, 12], [7, 7, 12, 9], [8, 8, 11, 11], [13, 13, 9, 10],
+            [12, 12, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [9, 9, 6, 3], [6, 6, 3, 5], [10, 10, 8, 4], [11, 11, 4, 7],
+            [5, 5, 12, 11], [7, 7, 10, 10], [8, 8, 9, 12], [13, 13, 11, 9],
+            [12, 12, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [9, 9, 6, 3], [10, 10, 3, 5], [7, 7, 8, 4], [11, 11, 4, 7],
+            [5, 5, 9, 9], [6, 6, 11, 12], [8, 8, 12, 10], [13, 13, 10, 11],
+            [12, 12, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [9, 9, 6, 3], [10, 10, 3, 5], [7, 7, 8, 4], [11, 11, 4, 7],
+            [5, 5, 12, 11], [6, 6, 10, 10], [8, 8, 9, 12], [13, 13, 11, 9],
+            [12, 12, 13, 13]],
+           [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8]
+            , [9, 9, 6, 3], [10, 10, 3, 5], [11, 11, 8, 4], [12, 12, 4, 7],
+            [5, 5, 9, 9], [6, 6, 12, 13], [7, 7, 11, 11], [8, 8, 13, 10],
+            [13, 13, 10, 12]],
+           [[1, 1, 0, 0], [0, 0, 2, 3], [4, 4, 3, 1], [5, 5, 1, 2], [2, 2, 4, 4]
+            , [3, 3, 6, 7], [7, 7, 7, 5], [6, 6, 5, 6]]]
+    for i  in range(len(t2)):
+        assert L[i].table == t2[i]
+
+    f = FpGroup(F, [x**2, y**3, (x*y)**7])
+    L = low_index_subgroups(f, 10, [x])
+    t3 = [[[0, 0, 0, 0]],
+          [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5], [4, 4, 5, 3],
+           [6, 6, 3, 4], [5, 5, 6, 6]],
+          [[0, 0, 1, 2], [1, 1, 2, 0], [3, 3, 0, 1], [2, 2, 4, 5], [6, 6, 5, 3],
+           [5, 5, 3, 4], [4, 4, 6, 6]],
+          [[0, 0, 1, 2], [3, 3, 2, 0], [4, 4, 0, 1], [1, 1, 5, 6], [2, 2, 7, 8],
+           [6, 6, 6, 3], [5, 5, 3, 5], [8, 8, 8, 4], [7, 7, 4, 7]]]
+    for i in range(len(t3)):
+        assert L[i].table == t3[i]
+
+
+def test_subgroup_presentations():
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**3, y**5, (x*y)**2])
+    H = [x*y, x**-1*y**-1*x*y*x]
+    p1 = reidemeister_presentation(f, H)
+    assert str(p1) == "((y_1, y_2), (y_1**2, y_2**3, y_2*y_1*y_2*y_1*y_2*y_1))"
+
+    H = f.subgroup(H)
+    assert (H.generators, H.relators) == p1
+
+    f = FpGroup(F, [x**3, y**3, (x*y)**3])
+    H = [x*y, x*y**-1]
+    p2 = reidemeister_presentation(f, H)
+    assert str(p2) == "((x_0, y_0), (x_0**3, y_0**3, x_0*y_0*x_0*y_0*x_0*y_0))"
+
+    f = FpGroup(F, [x**2*y**2, y**-1*x*y*x**-3])
+    H = [x]
+    p3 = reidemeister_presentation(f, H)
+    assert str(p3) == "((x_0,), (x_0**4,))"
+
+    f = FpGroup(F, [x**3*y**-3, (x*y)**3, (x*y**-1)**2])
+    H = [x]
+    p4 = reidemeister_presentation(f, H)
+    assert str(p4) == "((x_0,), (x_0**6,))"
+
+    # this presentation can be improved, the most simplified form
+    # of presentation is <a, b | a^11, b^2, (a*b)^3, (a^4*b*a^-5*b)^2>
+    # See [2] Pg 474 group PSL_2(11)
+    # This is the group PSL_2(11)
+    F, a, b, c = free_group("a, b, c")
+    f = FpGroup(F, [a**11, b**5, c**4, (b*c**2)**2, (a*b*c)**3, (a**4*c**2)**3, b**2*c**-1*b**-1*c, a**4*b**-1*a**-1*b])
+    H = [a, b, c**2]
+    gens, rels = reidemeister_presentation(f, H)
+    assert str(gens) == "(b_1, c_3)"
+    assert len(rels) == 18
+
+
+@slow
+def test_order():
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**4, y**2, x*y*x**-1*y])
+    assert f.order() == 8
+
+    f = FpGroup(F, [x*y*x**-1*y**-1, y**2])
+    assert f.order() is S.Infinity
+
+    F, a, b, c = free_group("a, b, c")
+    f = FpGroup(F, [a**250, b**2, c*b*c**-1*b, c**4, c**-1*a**-1*c*a, a**-1*b**-1*a*b])
+    assert f.order() == 2000
+
+    F, x = free_group("x")
+    f = FpGroup(F, [])
+    assert f.order() is S.Infinity
+
+    f = FpGroup(free_group('')[0], [])
+    assert f.order() == 1
+
+def test_fp_subgroup():
+    def _test_subgroup(K, T, S):
+        _gens = T(K.generators)
+        assert all(elem in S for elem in _gens)
+        assert T.is_injective()
+        assert T.image().order() == S.order()
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x**4, y**2, x*y*x**-1*y])
+    S = FpSubgroup(f, [x*y])
+    assert (x*y)**-3 in S
+    K, T = f.subgroup([x*y], homomorphism=True)
+    assert T(K.generators) == [y*x**-1]
+    _test_subgroup(K, T, S)
+
+    S = FpSubgroup(f, [x**-1*y*x])
+    assert x**-1*y**4*x in S
+    assert x**-1*y**4*x**2 not in S
+    K, T = f.subgroup([x**-1*y*x], homomorphism=True)
+    assert T(K.generators[0]**3) == y**3
+    _test_subgroup(K, T, S)
+
+    f = FpGroup(F, [x**3, y**5, (x*y)**2])
+    H = [x*y, x**-1*y**-1*x*y*x]
+    K, T = f.subgroup(H, homomorphism=True)
+    S = FpSubgroup(f, H)
+    _test_subgroup(K, T, S)
+
+def test_permutation_methods():
+    F, x, y = free_group("x, y")
+    # DihedralGroup(8)
+    G = FpGroup(F, [x**2, y**8, x*y*x**-1*y])
+    T = G._to_perm_group()[1]
+    assert T.is_isomorphism()
+    assert G.center() == [y**4]
+
+    # DiheadralGroup(4)
+    G = FpGroup(F, [x**2, y**4, x*y*x**-1*y])
+    S = FpSubgroup(G, G.normal_closure([x]))
+    assert x in S
+    assert y**-1*x*y in S
+
+    # Z_5xZ_4
+    G = FpGroup(F, [x*y*x**-1*y**-1, y**5, x**4])
+    assert G.is_abelian
+    assert G.is_solvable
+
+    # AlternatingGroup(5)
+    G = FpGroup(F, [x**3, y**2, (x*y)**5])
+    assert not G.is_solvable
+
+    # AlternatingGroup(4)
+    G = FpGroup(F, [x**3, y**2, (x*y)**3])
+    assert len(G.derived_series()) == 3
+    S = FpSubgroup(G, G.derived_subgroup())
+    assert S.order() == 4
+
+
+def test_simplify_presentation():
+    # ref #16083
+    G = simplify_presentation(FpGroup(FreeGroup([]), []))
+    assert not G.generators
+    assert not G.relators
+
+
+def test_cyclic():
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x*y, x**-1*y**-1*x*y*x])
+    assert f.is_cyclic
+    f = FpGroup(F, [x*y, x*y**-1])
+    assert f.is_cyclic
+    f = FpGroup(F, [x**4, y**2, x*y*x**-1*y])
+    assert not f.is_cyclic
+
+
+def test_abelian_invariants():
+    F, x, y = free_group("x, y")
+    f = FpGroup(F, [x*y, x**-1*y**-1*x*y*x])
+    assert f.abelian_invariants() == []
+    f = FpGroup(F, [x*y, x*y**-1])
+    assert f.abelian_invariants() == [2]
+    f = FpGroup(F, [x**4, y**2, x*y*x**-1*y])
+    assert f.abelian_invariants() == [2, 4]

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_galois.py

@@ -0,0 +1,82 @@
+"""Test groups defined by the galois module. """
+
+from sympy.combinatorics.galois import (
+    S4TransitiveSubgroups, S5TransitiveSubgroups, S6TransitiveSubgroups,
+    find_transitive_subgroups_of_S6,
+)
+from sympy.combinatorics.homomorphisms import is_isomorphic
+from sympy.combinatorics.named_groups import (
+    SymmetricGroup, AlternatingGroup, CyclicGroup,
+)
+
+
+def test_four_group():
+    G = S4TransitiveSubgroups.V.get_perm_group()
+    A4 = AlternatingGroup(4)
+    assert G.is_subgroup(A4)
+    assert G.degree == 4
+    assert G.is_transitive()
+    assert G.order() == 4
+    assert not G.is_cyclic
+
+
+def test_M20():
+    G = S5TransitiveSubgroups.M20.get_perm_group()
+    S5 = SymmetricGroup(5)
+    A5 = AlternatingGroup(5)
+    assert G.is_subgroup(S5)
+    assert not G.is_subgroup(A5)
+    assert G.degree == 5
+    assert G.is_transitive()
+    assert G.order() == 20
+
+
+# Setting this True means that for each of the transitive subgroups of S6,
+# we run a test not only on the fixed representation, but also on one freshly
+# generated by the search procedure.
+INCLUDE_SEARCH_REPS = False
+S6_randomized = {}
+if INCLUDE_SEARCH_REPS:
+    S6_randomized = find_transitive_subgroups_of_S6(*list(S6TransitiveSubgroups))
+
+
+def get_versions_of_S6_subgroup(name):
+    vers = [name.get_perm_group()]
+    if INCLUDE_SEARCH_REPS:
+        vers.append(S6_randomized[name])
+    return vers
+
+
+def test_S6_transitive_subgroups():
+    """
+    Test enough characteristics to distinguish all 16 transitive subgroups.
+    """
+    ts = S6TransitiveSubgroups
+    A6 = AlternatingGroup(6)
+    for name, alt, order, is_isom, not_isom in [
+        (ts.C6,     False,    6, CyclicGroup(6), None),
+        (ts.S3,     False,    6, SymmetricGroup(3), None),
+        (ts.D6,     False,   12, None, None),
+        (ts.A4,     True,    12, None, None),
+        (ts.G18,    False,   18, None, None),
+        (ts.A4xC2,  False,   24, None, SymmetricGroup(4)),
+        (ts.S4m,    False,   24, SymmetricGroup(4), None),
+        (ts.S4p,    True,    24, None, None),
+        (ts.G36m,   False,   36, None, None),
+        (ts.G36p,   True,    36, None, None),
+        (ts.S4xC2,  False,   48, None, None),
+        (ts.PSL2F5, True,    60, None, None),
+        (ts.G72,    False,   72, None, None),
+        (ts.PGL2F5, False,  120, None, None),
+        (ts.A6,     True,   360, None, None),
+        (ts.S6,     False,  720, None, None),
+    ]:
+        for G in get_versions_of_S6_subgroup(name):
+            assert G.is_transitive()
+            assert G.degree == 6
+            assert G.is_subgroup(A6) is alt
+            assert G.order() == order
+            if is_isom:
+                assert is_isomorphic(G, is_isom)
+            if not_isom:
+                assert not is_isomorphic(G, not_isom)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_graycode.py

@@ -0,0 +1,72 @@
+from sympy.combinatorics.graycode import (GrayCode, bin_to_gray,
+    random_bitstring, get_subset_from_bitstring, graycode_subsets,
+    gray_to_bin)
+from sympy.testing.pytest import raises
+
+def test_graycode():
+    g = GrayCode(2)
+    got = []
+    for i in g.generate_gray():
+        if i.startswith('0'):
+            g.skip()
+        got.append(i)
+    assert got == '00 11 10'.split()
+    a = GrayCode(6)
+    assert a.current == '0'*6
+    assert a.rank == 0
+    assert len(list(a.generate_gray())) == 64
+    codes = ['011001', '011011', '011010',
+    '011110', '011111', '011101', '011100', '010100', '010101', '010111',
+    '010110', '010010', '010011', '010001', '010000', '110000', '110001',
+    '110011', '110010', '110110', '110111', '110101', '110100', '111100',
+    '111101', '111111', '111110', '111010', '111011', '111001', '111000',
+    '101000', '101001', '101011', '101010', '101110', '101111', '101101',
+    '101100', '100100', '100101', '100111', '100110', '100010', '100011',
+    '100001', '100000']
+    assert list(a.generate_gray(start='011001')) == codes
+    assert list(
+        a.generate_gray(rank=GrayCode(6, start='011001').rank)) == codes
+    assert a.next().current == '000001'
+    assert a.next(2).current == '000011'
+    assert a.next(-1).current == '100000'
+
+    a = GrayCode(5, start='10010')
+    assert a.rank == 28
+    a = GrayCode(6, start='101000')
+    assert a.rank == 48
+
+    assert GrayCode(6, rank=4).current == '000110'
+    assert GrayCode(6, rank=4).rank == 4
+    assert [GrayCode(4, start=s).rank for s in
+            GrayCode(4).generate_gray()] == [0, 1, 2, 3, 4, 5, 6, 7, 8,
+                                             9, 10, 11, 12, 13, 14, 15]
+    a = GrayCode(15, rank=15)
+    assert a.current == '000000000001000'
+
+    assert bin_to_gray('111') == '100'
+
+    a = random_bitstring(5)
+    assert type(a) is str
+    assert len(a) == 5
+    assert all(i in ['0', '1'] for i in a)
+
+    assert get_subset_from_bitstring(
+        ['a', 'b', 'c', 'd'], '0011') == ['c', 'd']
+    assert get_subset_from_bitstring('abcd', '1001') == ['a', 'd']
+    assert list(graycode_subsets(['a', 'b', 'c'])) == \
+        [[], ['c'], ['b', 'c'], ['b'], ['a', 'b'], ['a', 'b', 'c'],
+         ['a', 'c'], ['a']]
+
+    raises(ValueError, lambda: GrayCode(0))
+    raises(ValueError, lambda: GrayCode(2.2))
+    raises(ValueError, lambda: GrayCode(2, start=[1, 1, 0]))
+    raises(ValueError, lambda: GrayCode(2, rank=2.5))
+    raises(ValueError, lambda: get_subset_from_bitstring(['c', 'a', 'c'], '1100'))
+    raises(ValueError, lambda: list(GrayCode(3).generate_gray(start="1111")))
+
+
+def test_live_issue_117():
+    assert bin_to_gray('0100') == '0110'
+    assert bin_to_gray('0101') == '0111'
+    for bits in ('0100', '0101'):
+        assert gray_to_bin(bin_to_gray(bits)) == bits

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_group_numbers.py

@@ -0,0 +1,27 @@
+from sympy.combinatorics.group_numbers import (is_nilpotent_number,
+    is_abelian_number, is_cyclic_number)
+from sympy.testing.pytest import raises
+from sympy import randprime
+
+
+def test_is_nilpotent_number():
+    assert is_nilpotent_number(21) == False
+    assert is_nilpotent_number(randprime(1, 30)**12) == True
+    raises(ValueError, lambda: is_nilpotent_number(-5))
+
+
+def test_is_abelian_number():
+    assert is_abelian_number(4) == True
+    assert is_abelian_number(randprime(1, 2000)**2) == True
+    assert is_abelian_number(randprime(1000, 100000)) == True
+    assert is_abelian_number(60) == False
+    assert is_abelian_number(24) == False
+    raises(ValueError, lambda: is_abelian_number(-5))
+
+
+def test_is_cyclic_number():
+    assert is_cyclic_number(15) == True
+    assert is_cyclic_number(randprime(1, 2000)**2) == False
+    assert is_cyclic_number(randprime(1000, 100000)) == True
+    assert is_cyclic_number(4) == False
+    raises(ValueError, lambda: is_cyclic_number(-5))

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_homomorphisms.py

@@ -0,0 +1,114 @@
+from sympy.combinatorics import Permutation
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.combinatorics.homomorphisms import homomorphism, group_isomorphism, is_isomorphic
+from sympy.combinatorics.free_groups import free_group
+from sympy.combinatorics.fp_groups import FpGroup
+from sympy.combinatorics.named_groups import AlternatingGroup, DihedralGroup, CyclicGroup
+from sympy.testing.pytest import raises
+
+def test_homomorphism():
+    # FpGroup -> PermutationGroup
+    F, a, b = free_group("a, b")
+    G = FpGroup(F, [a**3, b**3, (a*b)**2])
+
+    c = Permutation(3)(0, 1, 2)
+    d = Permutation(3)(1, 2, 3)
+    A = AlternatingGroup(4)
+    T = homomorphism(G, A, [a, b], [c, d])
+    assert T(a*b**2*a**-1) == c*d**2*c**-1
+    assert T.is_isomorphism()
+    assert T(T.invert(Permutation(3)(0, 2, 3))) == Permutation(3)(0, 2, 3)
+
+    T = homomorphism(G, AlternatingGroup(4), G.generators)
+    assert T.is_trivial()
+    assert T.kernel().order() == G.order()
+
+    E, e = free_group("e")
+    G = FpGroup(E, [e**8])
+    P = PermutationGroup([Permutation(0, 1, 2, 3), Permutation(0, 2)])
+    T = homomorphism(G, P, [e], [Permutation(0, 1, 2, 3)])
+    assert T.image().order() == 4
+    assert T(T.invert(Permutation(0, 2)(1, 3))) == Permutation(0, 2)(1, 3)
+
+    T = homomorphism(E, AlternatingGroup(4), E.generators, [c])
+    assert T.invert(c**2) == e**-1 #order(c) == 3 so c**2 == c**-1
+
+    # FreeGroup -> FreeGroup
+    T = homomorphism(F, E, [a], [e])
+    assert T(a**-2*b**4*a**2).is_identity
+
+    # FreeGroup -> FpGroup
+    G = FpGroup(F, [a*b*a**-1*b**-1])
+    T = homomorphism(F, G, F.generators, G.generators)
+    assert T.invert(a**-1*b**-1*a**2) == a*b**-1
+
+    # PermutationGroup -> PermutationGroup
+    D = DihedralGroup(8)
+    p = Permutation(0, 1, 2, 3, 4, 5, 6, 7)
+    P = PermutationGroup(p)
+    T = homomorphism(P, D, [p], [p])
+    assert T.is_injective()
+    assert not T.is_isomorphism()
+    assert T.invert(p**3) == p**3
+
+    T2 = homomorphism(F, P, [F.generators[0]], P.generators)
+    T = T.compose(T2)
+    assert T.domain == F
+    assert T.codomain == D
+    assert T(a*b) == p
+
+    D3 = DihedralGroup(3)
+    T = homomorphism(D3, D3, D3.generators, D3.generators)
+    assert T.is_isomorphism()
+
+
+def test_isomorphisms():
+
+    F, a, b = free_group("a, b")
+    E, c, d = free_group("c, d")
+    # Infinite groups with differently ordered relators.
+    G = FpGroup(F, [a**2, b**3])
+    H = FpGroup(F, [b**3, a**2])
+    assert is_isomorphic(G, H)
+
+    # Trivial Case
+    # FpGroup -> FpGroup
+    H = FpGroup(F, [a**3, b**3, (a*b)**2])
+    F, c, d = free_group("c, d")
+    G = FpGroup(F, [c**3, d**3, (c*d)**2])
+    check, T =  group_isomorphism(G, H)
+    assert check
+    assert T(c**3*d**2) == a**3*b**2
+
+    # FpGroup -> PermutationGroup
+    # FpGroup is converted to the equivalent isomorphic group.
+    F, a, b = free_group("a, b")
+    G = FpGroup(F, [a**3, b**3, (a*b)**2])
+    H = AlternatingGroup(4)
+    check, T = group_isomorphism(G, H)
+    assert check
+    assert T(b*a*b**-1*a**-1*b**-1) == Permutation(0, 2, 3)
+    assert T(b*a*b*a**-1*b**-1) == Permutation(0, 3, 2)
+
+    # PermutationGroup -> PermutationGroup
+    D = DihedralGroup(8)
+    p = Permutation(0, 1, 2, 3, 4, 5, 6, 7)
+    P = PermutationGroup(p)
+    assert not is_isomorphic(D, P)
+
+    A = CyclicGroup(5)
+    B = CyclicGroup(7)
+    assert not is_isomorphic(A, B)
+
+    # Two groups of the same prime order are isomorphic to each other.
+    G = FpGroup(F, [a, b**5])
+    H = CyclicGroup(5)
+    assert G.order() == H.order()
+    assert is_isomorphic(G, H)
+
+
+def test_check_homomorphism():
+    a = Permutation(1,2,3,4)
+    b = Permutation(1,3)
+    G = PermutationGroup([a, b])
+    raises(ValueError, lambda: homomorphism(G, G, [a], [a]))

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_named_groups.py

@@ -0,0 +1,70 @@
+from sympy.combinatorics.named_groups import (SymmetricGroup, CyclicGroup,
+                                              DihedralGroup, AlternatingGroup,
+                                              AbelianGroup, RubikGroup)
+from sympy.testing.pytest import raises
+
+
+def test_SymmetricGroup():
+    G = SymmetricGroup(5)
+    elements = list(G.generate())
+    assert (G.generators[0]).size == 5
+    assert len(elements) == 120
+    assert G.is_solvable is False
+    assert G.is_abelian is False
+    assert G.is_nilpotent is False
+    assert G.is_transitive() is True
+    H = SymmetricGroup(1)
+    assert H.order() == 1
+    L = SymmetricGroup(2)
+    assert L.order() == 2
+
+
+def test_CyclicGroup():
+    G = CyclicGroup(10)
+    elements = list(G.generate())
+    assert len(elements) == 10
+    assert (G.derived_subgroup()).order() == 1
+    assert G.is_abelian is True
+    assert G.is_solvable is True
+    assert G.is_nilpotent is True
+    H = CyclicGroup(1)
+    assert H.order() == 1
+    L = CyclicGroup(2)
+    assert L.order() == 2
+
+
+def test_DihedralGroup():
+    G = DihedralGroup(6)
+    elements = list(G.generate())
+    assert len(elements) == 12
+    assert G.is_transitive() is True
+    assert G.is_abelian is False
+    assert G.is_solvable is True
+    assert G.is_nilpotent is False
+    H = DihedralGroup(1)
+    assert H.order() == 2
+    L = DihedralGroup(2)
+    assert L.order() == 4
+    assert L.is_abelian is True
+    assert L.is_nilpotent is True
+
+
+def test_AlternatingGroup():
+    G = AlternatingGroup(5)
+    elements = list(G.generate())
+    assert len(elements) == 60
+    assert [perm.is_even for perm in elements] == [True]*60
+    H = AlternatingGroup(1)
+    assert H.order() == 1
+    L = AlternatingGroup(2)
+    assert L.order() == 1
+
+
+def test_AbelianGroup():
+    A = AbelianGroup(3, 3, 3)
+    assert A.order() == 27
+    assert A.is_abelian is True
+
+
+def test_RubikGroup():
+    raises(ValueError, lambda: RubikGroup(1))

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_partitions.py

@@ -0,0 +1,118 @@
+from sympy.core.sorting import ordered, default_sort_key
+from sympy.combinatorics.partitions import (Partition, IntegerPartition,
+                                            RGS_enum, RGS_unrank, RGS_rank,
+                                            random_integer_partition)
+from sympy.testing.pytest import raises
+from sympy.utilities.iterables import partitions
+from sympy.sets.sets import Set, FiniteSet
+
+
+def test_partition_constructor():
+    raises(ValueError, lambda: Partition([1, 1, 2]))
+    raises(ValueError, lambda: Partition([1, 2, 3], [2, 3, 4]))
+    raises(ValueError, lambda: Partition(1, 2, 3))
+    raises(ValueError, lambda: Partition(*list(range(3))))
+
+    assert Partition([1, 2, 3], [4, 5]) == Partition([4, 5], [1, 2, 3])
+    assert Partition({1, 2, 3}, {4, 5}) == Partition([1, 2, 3], [4, 5])
+
+    a = FiniteSet(1, 2, 3)
+    b = FiniteSet(4, 5)
+    assert Partition(a, b) == Partition([1, 2, 3], [4, 5])
+    assert Partition({a, b}) == Partition(FiniteSet(a, b))
+    assert Partition({a, b}) != Partition(a, b)
+
+def test_partition():
+    from sympy.abc import x
+
+    a = Partition([1, 2, 3], [4])
+    b = Partition([1, 2], [3, 4])
+    c = Partition([x])
+    l = [a, b, c]
+    l.sort(key=default_sort_key)
+    assert l == [c, a, b]
+    l.sort(key=lambda w: default_sort_key(w, order='rev-lex'))
+    assert l == [c, a, b]
+
+    assert (a == b) is False
+    assert a <= b
+    assert (a > b) is False
+    assert a != b
+    assert a < b
+
+    assert (a + 2).partition == [[1, 2], [3, 4]]
+    assert (b - 1).partition == [[1, 2, 4], [3]]
+
+    assert (a - 1).partition == [[1, 2, 3, 4]]
+    assert (a + 1).partition == [[1, 2, 4], [3]]
+    assert (b + 1).partition == [[1, 2], [3], [4]]
+
+    assert a.rank == 1
+    assert b.rank == 3
+
+    assert a.RGS == (0, 0, 0, 1)
+    assert b.RGS == (0, 0, 1, 1)
+
+
+def test_integer_partition():
+    # no zeros in partition
+    raises(ValueError, lambda: IntegerPartition(list(range(3))))
+    # check fails since 1 + 2 != 100
+    raises(ValueError, lambda: IntegerPartition(100, list(range(1, 3))))
+    a = IntegerPartition(8, [1, 3, 4])
+    b = a.next_lex()
+    c = IntegerPartition([1, 3, 4])
+    d = IntegerPartition(8, {1: 3, 3: 1, 2: 1})
+    assert a == c
+    assert a.integer == d.integer
+    assert a.conjugate == [3, 2, 2, 1]
+    assert (a == b) is False
+    assert a <= b
+    assert (a > b) is False
+    assert a != b
+
+    for i in range(1, 11):
+        next = set()
+        prev = set()
+        a = IntegerPartition([i])
+        ans = {IntegerPartition(p) for p in partitions(i)}
+        n = len(ans)
+        for j in range(n):
+            next.add(a)
+            a = a.next_lex()
+            IntegerPartition(i, a.partition)  # check it by giving i
+        for j in range(n):
+            prev.add(a)
+            a = a.prev_lex()
+            IntegerPartition(i, a.partition)  # check it by giving i
+        assert next == ans
+        assert prev == ans
+
+    assert IntegerPartition([1, 2, 3]).as_ferrers() == '###\n##\n#'
+    assert IntegerPartition([1, 1, 3]).as_ferrers('o') == 'ooo\no\no'
+    assert str(IntegerPartition([1, 1, 3])) == '[3, 1, 1]'
+    assert IntegerPartition([1, 1, 3]).partition == [3, 1, 1]
+
+    raises(ValueError, lambda: random_integer_partition(-1))
+    assert random_integer_partition(1) == [1]
+    assert random_integer_partition(10, seed=[1, 3, 2, 1, 5, 1]
+            ) == [5, 2, 1, 1, 1]
+
+
+def test_rgs():
+    raises(ValueError, lambda: RGS_unrank(-1, 3))
+    raises(ValueError, lambda: RGS_unrank(3, 0))
+    raises(ValueError, lambda: RGS_unrank(10, 1))
+
+    raises(ValueError, lambda: Partition.from_rgs(list(range(3)), list(range(2))))
+    raises(ValueError, lambda: Partition.from_rgs(list(range(1, 3)), list(range(2))))
+    assert RGS_enum(-1) == 0
+    assert RGS_enum(1) == 1
+    assert RGS_unrank(7, 5) == [0, 0, 1, 0, 2]
+    assert RGS_unrank(23, 14) == [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 2]
+    assert RGS_rank(RGS_unrank(40, 100)) == 40
+
+def test_ordered_partition_9608():
+    a = Partition([1, 2, 3], [4])
+    b = Partition([1, 2], [3, 4])
+    assert list(ordered([a,b], Set._infimum_key))

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_perm_groups.py

@@ -0,0 +1,1243 @@
+from sympy.core.containers import Tuple
+from sympy.combinatorics.generators import rubik_cube_generators
+from sympy.combinatorics.homomorphisms import is_isomorphic
+from sympy.combinatorics.named_groups import SymmetricGroup, CyclicGroup,\
+    DihedralGroup, AlternatingGroup, AbelianGroup, RubikGroup
+from sympy.combinatorics.perm_groups import (PermutationGroup,
+    _orbit_transversal, Coset, SymmetricPermutationGroup)
+from sympy.combinatorics.permutations import Permutation
+from sympy.combinatorics.polyhedron import tetrahedron as Tetra, cube
+from sympy.combinatorics.testutil import _verify_bsgs, _verify_centralizer,\
+    _verify_normal_closure
+from sympy.testing.pytest import skip, XFAIL, slow
+
+rmul = Permutation.rmul
+
+
+def test_has():
+    a = Permutation([1, 0])
+    G = PermutationGroup([a])
+    assert G.is_abelian
+    a = Permutation([2, 0, 1])
+    b = Permutation([2, 1, 0])
+    G = PermutationGroup([a, b])
+    assert not G.is_abelian
+
+    G = PermutationGroup([a])
+    assert G.has(a)
+    assert not G.has(b)
+
+    a = Permutation([2, 0, 1, 3, 4, 5])
+    b = Permutation([0, 2, 1, 3, 4])
+    assert PermutationGroup(a, b).degree == \
+        PermutationGroup(a, b).degree == 6
+
+    g = PermutationGroup(Permutation(0, 2, 1))
+    assert Tuple(1, g).has(g)
+
+
+def test_generate():
+    a = Permutation([1, 0])
+    g = list(PermutationGroup([a]).generate())
+    assert g == [Permutation([0, 1]), Permutation([1, 0])]
+    assert len(list(PermutationGroup(Permutation((0, 1))).generate())) == 1
+    g = PermutationGroup([a]).generate(method='dimino')
+    assert list(g) == [Permutation([0, 1]), Permutation([1, 0])]
+    a = Permutation([2, 0, 1])
+    b = Permutation([2, 1, 0])
+    G = PermutationGroup([a, b])
+    g = G.generate()
+    v1 = [p.array_form for p in list(g)]
+    v1.sort()
+    assert v1 == [[0, 1, 2], [0, 2, 1], [1, 0, 2], [1, 2, 0], [2, 0,
+        1], [2, 1, 0]]
+    v2 = list(G.generate(method='dimino', af=True))
+    assert v1 == sorted(v2)
+    a = Permutation([2, 0, 1, 3, 4, 5])
+    b = Permutation([2, 1, 3, 4, 5, 0])
+    g = PermutationGroup([a, b]).generate(af=True)
+    assert len(list(g)) == 360
+
+
+def test_order():
+    a = Permutation([2, 0, 1, 3, 4, 5, 6, 7, 8, 9])
+    b = Permutation([2, 1, 3, 4, 5, 6, 7, 8, 9, 0])
+    g = PermutationGroup([a, b])
+    assert g.order() == 1814400
+    assert PermutationGroup().order() == 1
+
+
+def test_equality():
+    p_1 = Permutation(0, 1, 3)
+    p_2 = Permutation(0, 2, 3)
+    p_3 = Permutation(0, 1, 2)
+    p_4 = Permutation(0, 1, 3)
+    g_1 = PermutationGroup(p_1, p_2)
+    g_2 = PermutationGroup(p_3, p_4)
+    g_3 = PermutationGroup(p_2, p_1)
+    g_4 = PermutationGroup(p_1, p_2)
+
+    assert g_1 != g_2
+    assert g_1.generators != g_2.generators
+    assert g_1.equals(g_2)
+    assert g_1 != g_3
+    assert g_1.equals(g_3)
+    assert g_1 == g_4
+
+
+def test_stabilizer():
+    S = SymmetricGroup(2)
+    H = S.stabilizer(0)
+    assert H.generators == [Permutation(1)]
+    a = Permutation([2, 0, 1, 3, 4, 5])
+    b = Permutation([2, 1, 3, 4, 5, 0])
+    G = PermutationGroup([a, b])
+    G0 = G.stabilizer(0)
+    assert G0.order() == 60
+
+    gens_cube = [[1, 3, 5, 7, 0, 2, 4, 6], [1, 3, 0, 2, 5, 7, 4, 6]]
+    gens = [Permutation(p) for p in gens_cube]
+    G = PermutationGroup(gens)
+    G2 = G.stabilizer(2)
+    assert G2.order() == 6
+    G2_1 = G2.stabilizer(1)
+    v = list(G2_1.generate(af=True))
+    assert v == [[0, 1, 2, 3, 4, 5, 6, 7], [3, 1, 2, 0, 7, 5, 6, 4]]
+
+    gens = (
+        (1, 2, 0, 4, 5, 3, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19),
+        (0, 1, 2, 3, 4, 5, 19, 6, 8, 9, 10, 11, 12, 13, 14,
+         15, 16, 7, 17, 18),
+        (0, 1, 2, 3, 4, 5, 6, 7, 9, 18, 16, 11, 12, 13, 14, 15, 8, 17, 10, 19))
+    gens = [Permutation(p) for p in gens]
+    G = PermutationGroup(gens)
+    G2 = G.stabilizer(2)
+    assert G2.order() == 181440
+    S = SymmetricGroup(3)
+    assert [G.order() for G in S.basic_stabilizers] == [6, 2]
+
+
+def test_center():
+    # the center of the dihedral group D_n is of order 2 for even n
+    for i in (4, 6, 10):
+        D = DihedralGroup(i)
+        assert (D.center()).order() == 2
+    # the center of the dihedral group D_n is of order 1 for odd n>2
+    for i in (3, 5, 7):
+        D = DihedralGroup(i)
+        assert (D.center()).order() == 1
+    # the center of an abelian group is the group itself
+    for i in (2, 3, 5):
+        for j in (1, 5, 7):
+            for k in (1, 1, 11):
+                G = AbelianGroup(i, j, k)
+                assert G.center().is_subgroup(G)
+    # the center of a nonabelian simple group is trivial
+    for i in(1, 5, 9):
+        A = AlternatingGroup(i)
+        assert (A.center()).order() == 1
+    # brute-force verifications
+    D = DihedralGroup(5)
+    A = AlternatingGroup(3)
+    C = CyclicGroup(4)
+    G.is_subgroup(D*A*C)
+    assert _verify_centralizer(G, G)
+
+
+def test_centralizer():
+    # the centralizer of the trivial group is the entire group
+    S = SymmetricGroup(2)
+    assert S.centralizer(Permutation(list(range(2)))).is_subgroup(S)
+    A = AlternatingGroup(5)
+    assert A.centralizer(Permutation(list(range(5)))).is_subgroup(A)
+    # a centralizer in the trivial group is the trivial group itself
+    triv = PermutationGroup([Permutation([0, 1, 2, 3])])
+    D = DihedralGroup(4)
+    assert triv.centralizer(D).is_subgroup(triv)
+    # brute-force verifications for centralizers of groups
+    for i in (4, 5, 6):
+        S = SymmetricGroup(i)
+        A = AlternatingGroup(i)
+        C = CyclicGroup(i)
+        D = DihedralGroup(i)
+        for gp in (S, A, C, D):
+            for gp2 in (S, A, C, D):
+                if not gp2.is_subgroup(gp):
+                    assert _verify_centralizer(gp, gp2)
+    # verify the centralizer for all elements of several groups
+    S = SymmetricGroup(5)
+    elements = list(S.generate_dimino())
+    for element in elements:
+        assert _verify_centralizer(S, element)
+    A = AlternatingGroup(5)
+    elements = list(A.generate_dimino())
+    for element in elements:
+        assert _verify_centralizer(A, element)
+    D = DihedralGroup(7)
+    elements = list(D.generate_dimino())
+    for element in elements:
+        assert _verify_centralizer(D, element)
+    # verify centralizers of small groups within small groups
+    small = []
+    for i in (1, 2, 3):
+        small.append(SymmetricGroup(i))
+        small.append(AlternatingGroup(i))
+        small.append(DihedralGroup(i))
+        small.append(CyclicGroup(i))
+    for gp in small:
+        for gp2 in small:
+            if gp.degree == gp2.degree:
+                assert _verify_centralizer(gp, gp2)
+
+
+def test_coset_rank():
+    gens_cube = [[1, 3, 5, 7, 0, 2, 4, 6], [1, 3, 0, 2, 5, 7, 4, 6]]
+    gens = [Permutation(p) for p in gens_cube]
+    G = PermutationGroup(gens)
+    i = 0
+    for h in G.generate(af=True):
+        rk = G.coset_rank(h)
+        assert rk == i
+        h1 = G.coset_unrank(rk, af=True)
+        assert h == h1
+        i += 1
+    assert G.coset_unrank(48) is None
+    assert G.coset_unrank(G.coset_rank(gens[0])) == gens[0]
+
+
+def test_coset_factor():
+    a = Permutation([0, 2, 1])
+    G = PermutationGroup([a])
+    c = Permutation([2, 1, 0])
+    assert not G.coset_factor(c)
+    assert G.coset_rank(c) is None
+
+    a = Permutation([2, 0, 1, 3, 4, 5])
+    b = Permutation([2, 1, 3, 4, 5, 0])
+    g = PermutationGroup([a, b])
+    assert g.order() == 360
+    d = Permutation([1, 0, 2, 3, 4, 5])
+    assert not g.coset_factor(d.array_form)
+    assert not g.contains(d)
+    assert Permutation(2) in G
+    c = Permutation([1, 0, 2, 3, 5, 4])
+    v = g.coset_factor(c, True)
+    tr = g.basic_transversals
+    p = Permutation.rmul(*[tr[i][v[i]] for i in range(len(g.base))])
+    assert p == c
+    v = g.coset_factor(c)
+    p = Permutation.rmul(*v)
+    assert p == c
+    assert g.contains(c)
+    G = PermutationGroup([Permutation([2, 1, 0])])
+    p = Permutation([1, 0, 2])
+    assert G.coset_factor(p) == []
+
+
+def test_orbits():
+    a = Permutation([2, 0, 1])
+    b = Permutation([2, 1, 0])
+    g = PermutationGroup([a, b])
+    assert g.orbit(0) == {0, 1, 2}
+    assert g.orbits() == [{0, 1, 2}]
+    assert g.is_transitive() and g.is_transitive(strict=False)
+    assert g.orbit_transversal(0) == \
+        [Permutation(
+            [0, 1, 2]), Permutation([2, 0, 1]), Permutation([1, 2, 0])]
+    assert g.orbit_transversal(0, True) == \
+        [(0, Permutation([0, 1, 2])), (2, Permutation([2, 0, 1])),
+        (1, Permutation([1, 2, 0]))]
+
+    G = DihedralGroup(6)
+    transversal, slps = _orbit_transversal(G.degree, G.generators, 0, True, slp=True)
+    for i, t in transversal:
+        slp = slps[i]
+        w = G.identity
+        for s in slp:
+            w = G.generators[s]*w
+        assert w == t
+
+    a = Permutation(list(range(1, 100)) + [0])
+    G = PermutationGroup([a])
+    assert [min(o) for o in G.orbits()] == [0]
+    G = PermutationGroup(rubik_cube_generators())
+    assert [min(o) for o in G.orbits()] == [0, 1]
+    assert not G.is_transitive() and not G.is_transitive(strict=False)
+    G = PermutationGroup([Permutation(0, 1, 3), Permutation(3)(0, 1)])
+    assert not G.is_transitive() and G.is_transitive(strict=False)
+    assert PermutationGroup(
+        Permutation(3)).is_transitive(strict=False) is False
+
+
+def test_is_normal():
+    gens_s5 = [Permutation(p) for p in [[1, 2, 3, 4, 0], [2, 1, 4, 0, 3]]]
+    G1 = PermutationGroup(gens_s5)
+    assert G1.order() == 120
+    gens_a5 = [Permutation(p) for p in [[1, 0, 3, 2, 4], [2, 1, 4, 3, 0]]]
+    G2 = PermutationGroup(gens_a5)
+    assert G2.order() == 60
+    assert G2.is_normal(G1)
+    gens3 = [Permutation(p) for p in [[2, 1, 3, 0, 4], [1, 2, 0, 3, 4]]]
+    G3 = PermutationGroup(gens3)
+    assert not G3.is_normal(G1)
+    assert G3.order() == 12
+    G4 = G1.normal_closure(G3.generators)
+    assert G4.order() == 60
+    gens5 = [Permutation(p) for p in [[1, 2, 3, 0, 4], [1, 2, 0, 3, 4]]]
+    G5 = PermutationGroup(gens5)
+    assert G5.order() == 24
+    G6 = G1.normal_closure(G5.generators)
+    assert G6.order() == 120
+    assert G1.is_subgroup(G6)
+    assert not G1.is_subgroup(G4)
+    assert G2.is_subgroup(G4)
+    I5 = PermutationGroup(Permutation(4))
+    assert I5.is_normal(G5)
+    assert I5.is_normal(G6, strict=False)
+    p1 = Permutation([1, 0, 2, 3, 4])
+    p2 = Permutation([0, 1, 2, 4, 3])
+    p3 = Permutation([3, 4, 2, 1, 0])
+    id_ = Permutation([0, 1, 2, 3, 4])
+    H = PermutationGroup([p1, p3])
+    H_n1 = PermutationGroup([p1, p2])
+    H_n2_1 = PermutationGroup(p1)
+    H_n2_2 = PermutationGroup(p2)
+    H_id = PermutationGroup(id_)
+    assert H_n1.is_normal(H)
+    assert H_n2_1.is_normal(H_n1)
+    assert H_n2_2.is_normal(H_n1)
+    assert H_id.is_normal(H_n2_1)
+    assert H_id.is_normal(H_n1)
+    assert H_id.is_normal(H)
+    assert not H_n2_1.is_normal(H)
+    assert not H_n2_2.is_normal(H)
+
+
+def test_eq():
+    a = [[1, 2, 0, 3, 4, 5], [1, 0, 2, 3, 4, 5], [2, 1, 0, 3, 4, 5], [
+        1, 2, 0, 3, 4, 5]]
+    a = [Permutation(p) for p in a + [[1, 2, 3, 4, 5, 0]]]
+    g = Permutation([1, 2, 3, 4, 5, 0])
+    G1, G2, G3 = [PermutationGroup(x) for x in [a[:2], a[2:4], [g, g**2]]]
+    assert G1.order() == G2.order() == G3.order() == 6
+    assert G1.is_subgroup(G2)
+    assert not G1.is_subgroup(G3)
+    G4 = PermutationGroup([Permutation([0, 1])])
+    assert not G1.is_subgroup(G4)
+    assert G4.is_subgroup(G1, 0)
+    assert PermutationGroup(g, g).is_subgroup(PermutationGroup(g))
+    assert SymmetricGroup(3).is_subgroup(SymmetricGroup(4), 0)
+    assert SymmetricGroup(3).is_subgroup(SymmetricGroup(3)*CyclicGroup(5), 0)
+    assert not CyclicGroup(5).is_subgroup(SymmetricGroup(3)*CyclicGroup(5), 0)
+    assert CyclicGroup(3).is_subgroup(SymmetricGroup(3)*CyclicGroup(5), 0)
+
+
+def test_derived_subgroup():
+    a = Permutation([1, 0, 2, 4, 3])
+    b = Permutation([0, 1, 3, 2, 4])
+    G = PermutationGroup([a, b])
+    C = G.derived_subgroup()
+    assert C.order() == 3
+    assert C.is_normal(G)
+    assert C.is_subgroup(G, 0)
+    assert not G.is_subgroup(C, 0)
+    gens_cube = [[1, 3, 5, 7, 0, 2, 4, 6], [1, 3, 0, 2, 5, 7, 4, 6]]
+    gens = [Permutation(p) for p in gens_cube]
+    G = PermutationGroup(gens)
+    C = G.derived_subgroup()
+    assert C.order() == 12
+
+
+def test_is_solvable():
+    a = Permutation([1, 2, 0])
+    b = Permutation([1, 0, 2])
+    G = PermutationGroup([a, b])
+    assert G.is_solvable
+    G = PermutationGroup([a])
+    assert G.is_solvable
+    a = Permutation([1, 2, 3, 4, 0])
+    b = Permutation([1, 0, 2, 3, 4])
+    G = PermutationGroup([a, b])
+    assert not G.is_solvable
+    P = SymmetricGroup(10)
+    S = P.sylow_subgroup(3)
+    assert S.is_solvable
+
+def test_rubik1():
+    gens = rubik_cube_generators()
+    gens1 = [gens[-1]] + [p**2 for p in gens[1:]]
+    G1 = PermutationGroup(gens1)
+    assert G1.order() == 19508428800
+    gens2 = [p**2 for p in gens]
+    G2 = PermutationGroup(gens2)
+    assert G2.order() == 663552
+    assert G2.is_subgroup(G1, 0)
+    C1 = G1.derived_subgroup()
+    assert C1.order() == 4877107200
+    assert C1.is_subgroup(G1, 0)
+    assert not G2.is_subgroup(C1, 0)
+
+    G = RubikGroup(2)
+    assert G.order() == 3674160
+
+
+@XFAIL
+def test_rubik():
+    skip('takes too much time')
+    G = PermutationGroup(rubik_cube_generators())
+    assert G.order() == 43252003274489856000
+    G1 = PermutationGroup(G[:3])
+    assert G1.order() == 170659735142400
+    assert not G1.is_normal(G)
+    G2 = G.normal_closure(G1.generators)
+    assert G2.is_subgroup(G)
+
+
+def test_direct_product():
+    C = CyclicGroup(4)
+    D = DihedralGroup(4)
+    G = C*C*C
+    assert G.order() == 64
+    assert G.degree == 12
+    assert len(G.orbits()) == 3
+    assert G.is_abelian is True
+    H = D*C
+    assert H.order() == 32
+    assert H.is_abelian is False
+
+
+def test_orbit_rep():
+    G = DihedralGroup(6)
+    assert G.orbit_rep(1, 3) in [Permutation([2, 3, 4, 5, 0, 1]),
+    Permutation([4, 3, 2, 1, 0, 5])]
+    H = CyclicGroup(4)*G
+    assert H.orbit_rep(1, 5) is False
+
+
+def test_schreier_vector():
+    G = CyclicGroup(50)
+    v = [0]*50
+    v[23] = -1
+    assert G.schreier_vector(23) == v
+    H = DihedralGroup(8)
+    assert H.schreier_vector(2) == [0, 1, -1, 0, 0, 1, 0, 0]
+    L = SymmetricGroup(4)
+    assert L.schreier_vector(1) == [1, -1, 0, 0]
+
+
+def test_random_pr():
+    D = DihedralGroup(6)
+    r = 11
+    n = 3
+    _random_prec_n = {}
+    _random_prec_n[0] = {'s': 7, 't': 3, 'x': 2, 'e': -1}
+    _random_prec_n[1] = {'s': 5, 't': 5, 'x': 1, 'e': -1}
+    _random_prec_n[2] = {'s': 3, 't': 4, 'x': 2, 'e': 1}
+    D._random_pr_init(r, n, _random_prec_n=_random_prec_n)
+    assert D._random_gens[11] == [0, 1, 2, 3, 4, 5]
+    _random_prec = {'s': 2, 't': 9, 'x': 1, 'e': -1}
+    assert D.random_pr(_random_prec=_random_prec) == \
+        Permutation([0, 5, 4, 3, 2, 1])
+
+
+def test_is_alt_sym():
+    G = DihedralGroup(10)
+    assert G.is_alt_sym() is False
+    assert G._eval_is_alt_sym_naive() is False
+    assert G._eval_is_alt_sym_naive(only_alt=True) is False
+    assert G._eval_is_alt_sym_naive(only_sym=True) is False
+
+    S = SymmetricGroup(10)
+    assert S._eval_is_alt_sym_naive() is True
+    assert S._eval_is_alt_sym_naive(only_alt=True) is False
+    assert S._eval_is_alt_sym_naive(only_sym=True) is True
+
+    N_eps = 10
+    _random_prec = {'N_eps': N_eps,
+        0: Permutation([[2], [1, 4], [0, 6, 7, 8, 9, 3, 5]]),
+        1: Permutation([[1, 8, 7, 6, 3, 5, 2, 9], [0, 4]]),
+        2: Permutation([[5, 8], [4, 7], [0, 1, 2, 3, 6, 9]]),
+        3: Permutation([[3], [0, 8, 2, 7, 4, 1, 6, 9, 5]]),
+        4: Permutation([[8], [4, 7, 9], [3, 6], [0, 5, 1, 2]]),
+        5: Permutation([[6], [0, 2, 4, 5, 1, 8, 3, 9, 7]]),
+        6: Permutation([[6, 9, 8], [4, 5], [1, 3, 7], [0, 2]]),
+        7: Permutation([[4], [0, 2, 9, 1, 3, 8, 6, 5, 7]]),
+        8: Permutation([[1, 5, 6, 3], [0, 2, 7, 8, 4, 9]]),
+        9: Permutation([[8], [6, 7], [2, 3, 4, 5], [0, 1, 9]])}
+    assert S.is_alt_sym(_random_prec=_random_prec) is True
+
+    A = AlternatingGroup(10)
+    assert A._eval_is_alt_sym_naive() is True
+    assert A._eval_is_alt_sym_naive(only_alt=True) is True
+    assert A._eval_is_alt_sym_naive(only_sym=True) is False
+
+    _random_prec = {'N_eps': N_eps,
+        0: Permutation([[1, 6, 4, 2, 7, 8, 5, 9, 3], [0]]),
+        1: Permutation([[1], [0, 5, 8, 4, 9, 2, 3, 6, 7]]),
+        2: Permutation([[1, 9, 8, 3, 2, 5], [0, 6, 7, 4]]),
+        3: Permutation([[6, 8, 9], [4, 5], [1, 3, 7, 2], [0]]),
+        4: Permutation([[8], [5], [4], [2, 6, 9, 3], [1], [0, 7]]),
+        5: Permutation([[3, 6], [0, 8, 1, 7, 5, 9, 4, 2]]),
+        6: Permutation([[5], [2, 9], [1, 8, 3], [0, 4, 7, 6]]),
+        7: Permutation([[1, 8, 4, 7, 2, 3], [0, 6, 9, 5]]),
+        8: Permutation([[5, 8, 7], [3], [1, 4, 2, 6], [0, 9]]),
+        9: Permutation([[4, 9, 6], [3, 8], [1, 2], [0, 5, 7]])}
+    assert A.is_alt_sym(_random_prec=_random_prec) is False
+
+    G = PermutationGroup(
+        Permutation(1, 3, size=8)(0, 2, 4, 6),
+        Permutation(5, 7, size=8)(0, 2, 4, 6))
+    assert G.is_alt_sym() is False
+
+    # Tests for monte-carlo c_n parameter setting, and which guarantees
+    # to give False.
+    G = DihedralGroup(10)
+    assert G._eval_is_alt_sym_monte_carlo() is False
+    G = DihedralGroup(20)
+    assert G._eval_is_alt_sym_monte_carlo() is False
+
+    # A dry-running test to check if it looks up for the updated cache.
+    G = DihedralGroup(6)
+    G.is_alt_sym()
+    assert G.is_alt_sym() is False
+
+
+def test_minimal_block():
+    D = DihedralGroup(6)
+    block_system = D.minimal_block([0, 3])
+    for i in range(3):
+        assert block_system[i] == block_system[i + 3]
+    S = SymmetricGroup(6)
+    assert S.minimal_block([0, 1]) == [0, 0, 0, 0, 0, 0]
+
+    assert Tetra.pgroup.minimal_block([0, 1]) == [0, 0, 0, 0]
+
+    P1 = PermutationGroup(Permutation(1, 5)(2, 4), Permutation(0, 1, 2, 3, 4, 5))
+    P2 = PermutationGroup(Permutation(0, 1, 2, 3, 4, 5), Permutation(1, 5)(2, 4))
+    assert P1.minimal_block([0, 2]) == [0, 1, 0, 1, 0, 1]
+    assert P2.minimal_block([0, 2]) == [0, 1, 0, 1, 0, 1]
+
+
+def test_minimal_blocks():
+    P = PermutationGroup(Permutation(1, 5)(2, 4), Permutation(0, 1, 2, 3, 4, 5))
+    assert P.minimal_blocks() == [[0, 1, 0, 1, 0, 1], [0, 1, 2, 0, 1, 2]]
+
+    P = SymmetricGroup(5)
+    assert P.minimal_blocks() == [[0]*5]
+
+    P = PermutationGroup(Permutation(0, 3))
+    assert P.minimal_blocks() is False
+
+
+def test_max_div():
+    S = SymmetricGroup(10)
+    assert S.max_div == 5
+
+
+def test_is_primitive():
+    S = SymmetricGroup(5)
+    assert S.is_primitive() is True
+    C = CyclicGroup(7)
+    assert C.is_primitive() is True
+
+    a = Permutation(0, 1, 2, size=6)
+    b = Permutation(3, 4, 5, size=6)
+    G = PermutationGroup(a, b)
+    assert G.is_primitive() is False
+
+
+def test_random_stab():
+    S = SymmetricGroup(5)
+    _random_el = Permutation([1, 3, 2, 0, 4])
+    _random_prec = {'rand': _random_el}
+    g = S.random_stab(2, _random_prec=_random_prec)
+    assert g == Permutation([1, 3, 2, 0, 4])
+    h = S.random_stab(1)
+    assert h(1) == 1
+
+
+def test_transitivity_degree():
+    perm = Permutation([1, 2, 0])
+    C = PermutationGroup([perm])
+    assert C.transitivity_degree == 1
+    gen1 = Permutation([1, 2, 0, 3, 4])
+    gen2 = Permutation([1, 2, 3, 4, 0])
+    # alternating group of degree 5
+    Alt = PermutationGroup([gen1, gen2])
+    assert Alt.transitivity_degree == 3
+
+
+def test_schreier_sims_random():
+    assert sorted(Tetra.pgroup.base) == [0, 1]
+
+    S = SymmetricGroup(3)
+    base = [0, 1]
+    strong_gens = [Permutation([1, 2, 0]), Permutation([1, 0, 2]),
+                  Permutation([0, 2, 1])]
+    assert S.schreier_sims_random(base, strong_gens, 5) == (base, strong_gens)
+    D = DihedralGroup(3)
+    _random_prec = {'g': [Permutation([2, 0, 1]), Permutation([1, 2, 0]),
+                         Permutation([1, 0, 2])]}
+    base = [0, 1]
+    strong_gens = [Permutation([1, 2, 0]), Permutation([2, 1, 0]),
+                  Permutation([0, 2, 1])]
+    assert D.schreier_sims_random([], D.generators, 2,
+           _random_prec=_random_prec) == (base, strong_gens)
+
+
+def test_baseswap():
+    S = SymmetricGroup(4)
+    S.schreier_sims()
+    base = S.base
+    strong_gens = S.strong_gens
+    assert base == [0, 1, 2]
+    deterministic = S.baseswap(base, strong_gens, 1, randomized=False)
+    randomized = S.baseswap(base, strong_gens, 1)
+    assert deterministic[0] == [0, 2, 1]
+    assert _verify_bsgs(S, deterministic[0], deterministic[1]) is True
+    assert randomized[0] == [0, 2, 1]
+    assert _verify_bsgs(S, randomized[0], randomized[1]) is True
+
+
+def test_schreier_sims_incremental():
+    identity = Permutation([0, 1, 2, 3, 4])
+    TrivialGroup = PermutationGroup([identity])
+    base, strong_gens = TrivialGroup.schreier_sims_incremental(base=[0, 1, 2])
+    assert _verify_bsgs(TrivialGroup, base, strong_gens) is True
+    S = SymmetricGroup(5)
+    base, strong_gens = S.schreier_sims_incremental(base=[0, 1, 2])
+    assert _verify_bsgs(S, base, strong_gens) is True
+    D = DihedralGroup(2)
+    base, strong_gens = D.schreier_sims_incremental(base=[1])
+    assert _verify_bsgs(D, base, strong_gens) is True
+    A = AlternatingGroup(7)
+    gens = A.generators[:]
+    gen0 = gens[0]
+    gen1 = gens[1]
+    gen1 = rmul(gen1, ~gen0)
+    gen0 = rmul(gen0, gen1)
+    gen1 = rmul(gen0, gen1)
+    base, strong_gens = A.schreier_sims_incremental(base=[0, 1], gens=gens)
+    assert _verify_bsgs(A, base, strong_gens) is True
+    C = CyclicGroup(11)
+    gen = C.generators[0]
+    base, strong_gens = C.schreier_sims_incremental(gens=[gen**3])
+    assert _verify_bsgs(C, base, strong_gens) is True
+
+
+def _subgroup_search(i, j, k):
+    prop_true = lambda x: True
+    prop_fix_points = lambda x: [x(point) for point in points] == points
+    prop_comm_g = lambda x: rmul(x, g) == rmul(g, x)
+    prop_even = lambda x: x.is_even
+    for i in range(i, j, k):
+        S = SymmetricGroup(i)
+        A = AlternatingGroup(i)
+        C = CyclicGroup(i)
+        Sym = S.subgroup_search(prop_true)
+        assert Sym.is_subgroup(S)
+        Alt = S.subgroup_search(prop_even)
+        assert Alt.is_subgroup(A)
+        Sym = S.subgroup_search(prop_true, init_subgroup=C)
+        assert Sym.is_subgroup(S)
+        points = [7]
+        assert S.stabilizer(7).is_subgroup(S.subgroup_search(prop_fix_points))
+        points = [3, 4]
+        assert S.stabilizer(3).stabilizer(4).is_subgroup(
+            S.subgroup_search(prop_fix_points))
+        points = [3, 5]
+        fix35 = A.subgroup_search(prop_fix_points)
+        points = [5]
+        fix5 = A.subgroup_search(prop_fix_points)
+        assert A.subgroup_search(prop_fix_points, init_subgroup=fix35
+            ).is_subgroup(fix5)
+        base, strong_gens = A.schreier_sims_incremental()
+        g = A.generators[0]
+        comm_g = \
+            A.subgroup_search(prop_comm_g, base=base, strong_gens=strong_gens)
+        assert _verify_bsgs(comm_g, base, comm_g.generators) is True
+        assert [prop_comm_g(gen) is True for gen in comm_g.generators]
+
+
+def test_subgroup_search():
+    _subgroup_search(10, 15, 2)
+
+
+@XFAIL
+def test_subgroup_search2():
+    skip('takes too much time')
+    _subgroup_search(16, 17, 1)
+
+
+def test_normal_closure():
+    # the normal closure of the trivial group is trivial
+    S = SymmetricGroup(3)
+    identity = Permutation([0, 1, 2])
+    closure = S.normal_closure(identity)
+    assert closure.is_trivial
+    # the normal closure of the entire group is the entire group
+    A = AlternatingGroup(4)
+    assert A.normal_closure(A).is_subgroup(A)
+    # brute-force verifications for subgroups
+    for i in (3, 4, 5):
+        S = SymmetricGroup(i)
+        A = AlternatingGroup(i)
+        D = DihedralGroup(i)
+        C = CyclicGroup(i)
+        for gp in (A, D, C):
+            assert _verify_normal_closure(S, gp)
+    # brute-force verifications for all elements of a group
+    S = SymmetricGroup(5)
+    elements = list(S.generate_dimino())
+    for element in elements:
+        assert _verify_normal_closure(S, element)
+    # small groups
+    small = []
+    for i in (1, 2, 3):
+        small.append(SymmetricGroup(i))
+        small.append(AlternatingGroup(i))
+        small.append(DihedralGroup(i))
+        small.append(CyclicGroup(i))
+    for gp in small:
+        for gp2 in small:
+            if gp2.is_subgroup(gp, 0) and gp2.degree == gp.degree:
+                assert _verify_normal_closure(gp, gp2)
+
+
+def test_derived_series():
+    # the derived series of the trivial group consists only of the trivial group
+    triv = PermutationGroup([Permutation([0, 1, 2])])
+    assert triv.derived_series()[0].is_subgroup(triv)
+    # the derived series for a simple group consists only of the group itself
+    for i in (5, 6, 7):
+        A = AlternatingGroup(i)
+        assert A.derived_series()[0].is_subgroup(A)
+    # the derived series for S_4 is S_4 > A_4 > K_4 > triv
+    S = SymmetricGroup(4)
+    series = S.derived_series()
+    assert series[1].is_subgroup(AlternatingGroup(4))
+    assert series[2].is_subgroup(DihedralGroup(2))
+    assert series[3].is_trivial
+
+
+def test_lower_central_series():
+    # the lower central series of the trivial group consists of the trivial
+    # group
+    triv = PermutationGroup([Permutation([0, 1, 2])])
+    assert triv.lower_central_series()[0].is_subgroup(triv)
+    # the lower central series of a simple group consists of the group itself
+    for i in (5, 6, 7):
+        A = AlternatingGroup(i)
+        assert A.lower_central_series()[0].is_subgroup(A)
+    # GAP-verified example
+    S = SymmetricGroup(6)
+    series = S.lower_central_series()
+    assert len(series) == 2
+    assert series[1].is_subgroup(AlternatingGroup(6))
+
+
+def test_commutator():
+    # the commutator of the trivial group and the trivial group is trivial
+    S = SymmetricGroup(3)
+    triv = PermutationGroup([Permutation([0, 1, 2])])
+    assert S.commutator(triv, triv).is_subgroup(triv)
+    # the commutator of the trivial group and any other group is again trivial
+    A = AlternatingGroup(3)
+    assert S.commutator(triv, A).is_subgroup(triv)
+    # the commutator is commutative
+    for i in (3, 4, 5):
+        S = SymmetricGroup(i)
+        A = AlternatingGroup(i)
+        D = DihedralGroup(i)
+        assert S.commutator(A, D).is_subgroup(S.commutator(D, A))
+    # the commutator of an abelian group is trivial
+    S = SymmetricGroup(7)
+    A1 = AbelianGroup(2, 5)
+    A2 = AbelianGroup(3, 4)
+    triv = PermutationGroup([Permutation([0, 1, 2, 3, 4, 5, 6])])
+    assert S.commutator(A1, A1).is_subgroup(triv)
+    assert S.commutator(A2, A2).is_subgroup(triv)
+    # examples calculated by hand
+    S = SymmetricGroup(3)
+    A = AlternatingGroup(3)
+    assert S.commutator(A, S).is_subgroup(A)
+
+
+def test_is_nilpotent():
+    # every abelian group is nilpotent
+    for i in (1, 2, 3):
+        C = CyclicGroup(i)
+        Ab = AbelianGroup(i, i + 2)
+        assert C.is_nilpotent
+        assert Ab.is_nilpotent
+    Ab = AbelianGroup(5, 7, 10)
+    assert Ab.is_nilpotent
+    # A_5 is not solvable and thus not nilpotent
+    assert AlternatingGroup(5).is_nilpotent is False
+
+
+def test_is_trivial():
+    for i in range(5):
+        triv = PermutationGroup([Permutation(list(range(i)))])
+        assert triv.is_trivial
+
+
+def test_pointwise_stabilizer():
+    S = SymmetricGroup(2)
+    stab = S.pointwise_stabilizer([0])
+    assert stab.generators == [Permutation(1)]
+    S = SymmetricGroup(5)
+    points = []
+    stab = S
+    for point in (2, 0, 3, 4, 1):
+        stab = stab.stabilizer(point)
+        points.append(point)
+        assert S.pointwise_stabilizer(points).is_subgroup(stab)
+
+
+def test_make_perm():
+    assert cube.pgroup.make_perm(5, seed=list(range(5))) == \
+        Permutation([4, 7, 6, 5, 0, 3, 2, 1])
+    assert cube.pgroup.make_perm(7, seed=list(range(7))) == \
+        Permutation([6, 7, 3, 2, 5, 4, 0, 1])
+
+
+def test_elements():
+    from sympy.sets.sets import FiniteSet
+
+    p = Permutation(2, 3)
+    assert PermutationGroup(p).elements == {Permutation(3), Permutation(2, 3)}
+    assert FiniteSet(*PermutationGroup(p).elements) \
+        == FiniteSet(Permutation(2, 3), Permutation(3))
+
+
+def test_is_group():
+    assert PermutationGroup(Permutation(1,2), Permutation(2,4)).is_group is True
+    assert SymmetricGroup(4).is_group is True
+
+
+def test_PermutationGroup():
+    assert PermutationGroup() == PermutationGroup(Permutation())
+    assert (PermutationGroup() == 0) is False
+
+
+def test_coset_transvesal():
+    G = AlternatingGroup(5)
+    H = PermutationGroup(Permutation(0,1,2),Permutation(1,2)(3,4))
+    assert G.coset_transversal(H) == \
+        [Permutation(4), Permutation(2, 3, 4), Permutation(2, 4, 3),
+         Permutation(1, 2, 4), Permutation(4)(1, 2, 3), Permutation(1, 3)(2, 4),
+         Permutation(0, 1, 2, 3, 4), Permutation(0, 1, 2, 4, 3),
+         Permutation(0, 1, 3, 2, 4), Permutation(0, 2, 4, 1, 3)]
+
+
+def test_coset_table():
+    G = PermutationGroup(Permutation(0,1,2,3), Permutation(0,1,2),
+         Permutation(0,4,2,7), Permutation(5,6), Permutation(0,7));
+    H = PermutationGroup(Permutation(0,1,2,3), Permutation(0,7))
+    assert G.coset_table(H) == \
+        [[0, 0, 0, 0, 1, 2, 3, 3, 0, 0], [4, 5, 2, 5, 6, 0, 7, 7, 1, 1],
+         [5, 4, 5, 1, 0, 6, 8, 8, 6, 6], [3, 3, 3, 3, 7, 8, 0, 0, 3, 3],
+         [2, 1, 4, 4, 4, 4, 9, 9, 4, 4], [1, 2, 1, 2, 5, 5, 10, 10, 5, 5],
+         [6, 6, 6, 6, 2, 1, 11, 11, 2, 2], [9, 10, 8, 10, 11, 3, 1, 1, 7, 7],
+         [10, 9, 10, 7, 3, 11, 2, 2, 11, 11], [8, 7, 9, 9, 9, 9, 4, 4, 9, 9],
+         [7, 8, 7, 8, 10, 10, 5, 5, 10, 10], [11, 11, 11, 11, 8, 7, 6, 6, 8, 8]]
+
+
+def test_subgroup():
+    G = PermutationGroup(Permutation(0,1,2), Permutation(0,2,3))
+    H = G.subgroup([Permutation(0,1,3)])
+    assert H.is_subgroup(G)
+
+
+def test_generator_product():
+    G = SymmetricGroup(5)
+    p = Permutation(0, 2, 3)(1, 4)
+    gens = G.generator_product(p)
+    assert all(g in G.strong_gens for g in gens)
+    w = G.identity
+    for g in gens:
+        w = g*w
+    assert w == p
+
+
+def test_sylow_subgroup():
+    P = PermutationGroup(Permutation(1, 5)(2, 4), Permutation(0, 1, 2, 3, 4, 5))
+    S = P.sylow_subgroup(2)
+    assert S.order() == 4
+
+    P = DihedralGroup(12)
+    S = P.sylow_subgroup(3)
+    assert S.order() == 3
+
+    P = PermutationGroup(
+        Permutation(1, 5)(2, 4), Permutation(0, 1, 2, 3, 4, 5), Permutation(0, 2))
+    S = P.sylow_subgroup(3)
+    assert S.order() == 9
+    S = P.sylow_subgroup(2)
+    assert S.order() == 8
+
+    P = SymmetricGroup(10)
+    S = P.sylow_subgroup(2)
+    assert S.order() == 256
+    S = P.sylow_subgroup(3)
+    assert S.order() == 81
+    S = P.sylow_subgroup(5)
+    assert S.order() == 25
+
+    # the length of the lower central series
+    # of a p-Sylow subgroup of Sym(n) grows with
+    # the highest exponent exp of p such
+    # that n >= p**exp
+    exp = 1
+    length = 0
+    for i in range(2, 9):
+        P = SymmetricGroup(i)
+        S = P.sylow_subgroup(2)
+        ls = S.lower_central_series()
+        if i // 2**exp > 0:
+            # length increases with exponent
+            assert len(ls) > length
+            length = len(ls)
+            exp += 1
+        else:
+            assert len(ls) == length
+
+    G = SymmetricGroup(100)
+    S = G.sylow_subgroup(3)
+    assert G.order() % S.order() == 0
+    assert G.order()/S.order() % 3 > 0
+
+    G = AlternatingGroup(100)
+    S = G.sylow_subgroup(2)
+    assert G.order() % S.order() == 0
+    assert G.order()/S.order() % 2 > 0
+
+    G = DihedralGroup(18)
+    S = G.sylow_subgroup(p=2)
+    assert S.order() == 4
+
+    G = DihedralGroup(50)
+    S = G.sylow_subgroup(p=2)
+    assert S.order() == 4
+
+
+@slow
+def test_presentation():
+    def _test(P):
+        G = P.presentation()
+        return G.order() == P.order()
+
+    def _strong_test(P):
+        G = P.strong_presentation()
+        chk = len(G.generators) == len(P.strong_gens)
+        return chk and G.order() == P.order()
+
+    P = PermutationGroup(Permutation(0,1,5,2)(3,7,4,6), Permutation(0,3,5,4)(1,6,2,7))
+    assert _test(P)
+
+    P = AlternatingGroup(5)
+    assert _test(P)
+
+    P = SymmetricGroup(5)
+    assert _test(P)
+
+    P = PermutationGroup(
+        [Permutation(0,3,1,2), Permutation(3)(0,1), Permutation(0,1)(2,3)])
+    assert _strong_test(P)
+
+    P = DihedralGroup(6)
+    assert _strong_test(P)
+
+    a = Permutation(0,1)(2,3)
+    b = Permutation(0,2)(3,1)
+    c = Permutation(4,5)
+    P = PermutationGroup(c, a, b)
+    assert _strong_test(P)
+
+
+def test_polycyclic():
+    a = Permutation([0, 1, 2])
+    b = Permutation([2, 1, 0])
+    G = PermutationGroup([a, b])
+    assert G.is_polycyclic is True
+
+    a = Permutation([1, 2, 3, 4, 0])
+    b = Permutation([1, 0, 2, 3, 4])
+    G = PermutationGroup([a, b])
+    assert G.is_polycyclic is False
+
+
+def test_elementary():
+    a = Permutation([1, 5, 2, 0, 3, 6, 4])
+    G = PermutationGroup([a])
+    assert G.is_elementary(7) is False
+
+    a = Permutation(0, 1)(2, 3)
+    b = Permutation(0, 2)(3, 1)
+    G = PermutationGroup([a, b])
+    assert G.is_elementary(2) is True
+    c = Permutation(4, 5, 6)
+    G = PermutationGroup([a, b, c])
+    assert G.is_elementary(2) is False
+
+    G = SymmetricGroup(4).sylow_subgroup(2)
+    assert G.is_elementary(2) is False
+    H = AlternatingGroup(4).sylow_subgroup(2)
+    assert H.is_elementary(2) is True
+
+
+def test_perfect():
+    G = AlternatingGroup(3)
+    assert G.is_perfect is False
+    G = AlternatingGroup(5)
+    assert G.is_perfect is True
+
+
+def test_index():
+    G = PermutationGroup(Permutation(0,1,2), Permutation(0,2,3))
+    H = G.subgroup([Permutation(0,1,3)])
+    assert G.index(H) == 4
+
+
+def test_cyclic():
+    G = SymmetricGroup(2)
+    assert G.is_cyclic
+    G = AbelianGroup(3, 7)
+    assert G.is_cyclic
+    G = AbelianGroup(7, 7)
+    assert not G.is_cyclic
+    G = AlternatingGroup(3)
+    assert G.is_cyclic
+    G = AlternatingGroup(4)
+    assert not G.is_cyclic
+
+    # Order less than 6
+    G = PermutationGroup(Permutation(0, 1, 2), Permutation(0, 2, 1))
+    assert G.is_cyclic
+    G = PermutationGroup(
+        Permutation(0, 1, 2, 3),
+        Permutation(0, 2)(1, 3)
+    )
+    assert G.is_cyclic
+    G = PermutationGroup(
+        Permutation(3),
+        Permutation(0, 1)(2, 3),
+        Permutation(0, 2)(1, 3),
+        Permutation(0, 3)(1, 2)
+    )
+    assert G.is_cyclic is False
+
+    # Order 15
+    G = PermutationGroup(
+        Permutation(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14),
+        Permutation(0, 2, 4, 6, 8, 10, 12, 14, 1, 3, 5, 7, 9, 11, 13)
+    )
+    assert G.is_cyclic
+
+    # Distinct prime orders
+    assert PermutationGroup._distinct_primes_lemma([3, 5]) is True
+    assert PermutationGroup._distinct_primes_lemma([5, 7]) is True
+    assert PermutationGroup._distinct_primes_lemma([2, 3]) is None
+    assert PermutationGroup._distinct_primes_lemma([3, 5, 7]) is None
+    assert PermutationGroup._distinct_primes_lemma([5, 7, 13]) is True
+
+    G = PermutationGroup(
+        Permutation(0, 1, 2, 3),
+        Permutation(0, 2)(1, 3))
+    assert G.is_cyclic
+    assert G._is_abelian
+
+    # Non-abelian and therefore not cyclic
+    G = PermutationGroup(*SymmetricGroup(3).generators)
+    assert G.is_cyclic is False
+
+    # Abelian and cyclic
+    G = PermutationGroup(
+        Permutation(0, 1, 2, 3),
+        Permutation(4, 5, 6)
+    )
+    assert G.is_cyclic
+
+    # Abelian but not cyclic
+    G = PermutationGroup(
+        Permutation(0, 1),
+        Permutation(2, 3),
+        Permutation(4, 5, 6)
+    )
+    assert G.is_cyclic is False
+
+
+def test_dihedral():
+    G = SymmetricGroup(2)
+    assert G.is_dihedral
+    G = SymmetricGroup(3)
+    assert G.is_dihedral
+
+    G = AbelianGroup(2, 2)
+    assert G.is_dihedral
+    G = CyclicGroup(4)
+    assert not G.is_dihedral
+
+    G = AbelianGroup(3, 5)
+    assert not G.is_dihedral
+    G = AbelianGroup(2)
+    assert G.is_dihedral
+    G = AbelianGroup(6)
+    assert not G.is_dihedral
+
+    # D6, generated by two adjacent flips
+    G = PermutationGroup(
+        Permutation(1, 5)(2, 4),
+        Permutation(0, 1)(3, 4)(2, 5))
+    assert G.is_dihedral
+
+    # D7, generated by a flip and a rotation
+    G = PermutationGroup(
+        Permutation(1, 6)(2, 5)(3, 4),
+        Permutation(0, 1, 2, 3, 4, 5, 6))
+    assert G.is_dihedral
+
+    # S4, presented by three generators, fails due to having exactly 9
+    # elements of order 2:
+    G = PermutationGroup(
+        Permutation(0, 1), Permutation(0, 2),
+        Permutation(0, 3))
+    assert not G.is_dihedral
+
+    # D7, given by three generators
+    G = PermutationGroup(
+        Permutation(1, 6)(2, 5)(3, 4),
+        Permutation(2, 0)(3, 6)(4, 5),
+        Permutation(0, 1, 2, 3, 4, 5, 6))
+    assert G.is_dihedral
+
+
+def test_abelian_invariants():
+    G = AbelianGroup(2, 3, 4)
+    assert G.abelian_invariants() == [2, 3, 4]
+    G=PermutationGroup([Permutation(1, 2, 3, 4), Permutation(1, 2), Permutation(5, 6)])
+    assert G.abelian_invariants() == [2, 2]
+    G = AlternatingGroup(7)
+    assert G.abelian_invariants() == []
+    G = AlternatingGroup(4)
+    assert G.abelian_invariants() == [3]
+    G = DihedralGroup(4)
+    assert G.abelian_invariants() == [2, 2]
+
+    G = PermutationGroup([Permutation(1, 2, 3, 4, 5, 6, 7)])
+    assert G.abelian_invariants() == [7]
+    G = DihedralGroup(12)
+    S = G.sylow_subgroup(3)
+    assert S.abelian_invariants() == [3]
+    G = PermutationGroup(Permutation(0, 1, 2), Permutation(0, 2, 3))
+    assert G.abelian_invariants() == [3]
+    G = PermutationGroup([Permutation(0, 1), Permutation(0, 2, 4, 6)(1, 3, 5, 7)])
+    assert G.abelian_invariants() == [2, 4]
+    G = SymmetricGroup(30)
+    S = G.sylow_subgroup(2)
+    assert S.abelian_invariants() == [2, 2, 2, 2, 2, 2, 2, 2, 2, 2]
+    S = G.sylow_subgroup(3)
+    assert S.abelian_invariants() == [3, 3, 3, 3]
+    S = G.sylow_subgroup(5)
+    assert S.abelian_invariants() == [5, 5, 5]
+
+
+def test_composition_series():
+    a = Permutation(1, 2, 3)
+    b = Permutation(1, 2)
+    G = PermutationGroup([a, b])
+    comp_series = G.composition_series()
+    assert comp_series == G.derived_series()
+    # The first group in the composition series is always the group itself and
+    # the last group in the series is the trivial group.
+    S = SymmetricGroup(4)
+    assert S.composition_series()[0] == S
+    assert len(S.composition_series()) == 5
+    A = AlternatingGroup(4)
+    assert A.composition_series()[0] == A
+    assert len(A.composition_series()) == 4
+
+    # the composition series for C_8 is C_8 > C_4 > C_2 > triv
+    G = CyclicGroup(8)
+    series = G.composition_series()
+    assert is_isomorphic(series[1], CyclicGroup(4))
+    assert is_isomorphic(series[2], CyclicGroup(2))
+    assert series[3].is_trivial
+
+
+def test_is_symmetric():
+    a = Permutation(0, 1, 2)
+    b = Permutation(0, 1, size=3)
+    assert PermutationGroup(a, b).is_symmetric is True
+
+    a = Permutation(0, 2, 1)
+    b = Permutation(1, 2, size=3)
+    assert PermutationGroup(a, b).is_symmetric is True
+
+    a = Permutation(0, 1, 2, 3)
+    b = Permutation(0, 3)(1, 2)
+    assert PermutationGroup(a, b).is_symmetric is False
+
+def test_conjugacy_class():
+    S = SymmetricGroup(4)
+    x = Permutation(1, 2, 3)
+    C = {Permutation(0, 1, 2, size = 4), Permutation(0, 1, 3),
+             Permutation(0, 2, 1, size = 4), Permutation(0, 2, 3),
+             Permutation(0, 3, 1), Permutation(0, 3, 2),
+             Permutation(1, 2, 3), Permutation(1, 3, 2)}
+    assert S.conjugacy_class(x) == C
+
+def test_conjugacy_classes():
+    S = SymmetricGroup(3)
+    expected = [{Permutation(size = 3)},
+         {Permutation(0, 1, size = 3), Permutation(0, 2), Permutation(1, 2)},
+         {Permutation(0, 1, 2), Permutation(0, 2, 1)}]
+    computed = S.conjugacy_classes()
+
+    assert len(expected) == len(computed)
+    assert all(e in computed for e in expected)
+
+def test_coset_class():
+    a = Permutation(1, 2)
+    b = Permutation(0, 1)
+    G = PermutationGroup([a, b])
+    #Creating right coset
+    rht_coset = G*a
+    #Checking whether it is left coset or right coset
+    assert rht_coset.is_right_coset
+    assert not rht_coset.is_left_coset
+    #Creating list representation of coset
+    list_repr = rht_coset.as_list()
+    expected = [Permutation(0, 2), Permutation(0, 2, 1), Permutation(1, 2),
+                Permutation(2), Permutation(2)(0, 1), Permutation(0, 1, 2)]
+    for ele in list_repr:
+        assert ele in expected
+    #Creating left coset
+    left_coset = a*G
+    #Checking whether it is left coset or right coset
+    assert not left_coset.is_right_coset
+    assert left_coset.is_left_coset
+    #Creating list representation of Coset
+    list_repr = left_coset.as_list()
+    expected = [Permutation(2)(0, 1), Permutation(0, 1, 2), Permutation(1, 2),
+    Permutation(2), Permutation(0, 2), Permutation(0, 2, 1)]
+    for ele in list_repr:
+        assert ele in expected
+
+    G = PermutationGroup(Permutation(1, 2, 3, 4), Permutation(2, 3, 4))
+    H = PermutationGroup(Permutation(1, 2, 3, 4))
+    g = Permutation(1, 3)(2, 4)
+    rht_coset = Coset(g, H, G, dir='+')
+    assert rht_coset.is_right_coset
+    list_repr = rht_coset.as_list()
+    expected = [Permutation(1, 2, 3, 4), Permutation(4), Permutation(1, 3)(2, 4),
+    Permutation(1, 4, 3, 2)]
+    for ele in list_repr:
+        assert ele in expected
+
+def test_symmetricpermutationgroup():
+    a = SymmetricPermutationGroup(5)
+    assert a.degree == 5
+    assert a.order() == 120
+    assert a.identity() == Permutation(4)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_polyhedron.py

@@ -0,0 +1,105 @@
+from sympy.core.symbol import symbols
+from sympy.sets.sets import FiniteSet
+from sympy.combinatorics.polyhedron import (Polyhedron,
+    tetrahedron, cube as square, octahedron, dodecahedron, icosahedron,
+    cube_faces)
+from sympy.combinatorics.permutations import Permutation
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.testing.pytest import raises
+
+rmul = Permutation.rmul
+
+
+def test_polyhedron():
+    raises(ValueError, lambda: Polyhedron(list('ab'),
+        pgroup=[Permutation([0])]))
+    pgroup = [Permutation([[0, 7, 2, 5], [6, 1, 4, 3]]),
+              Permutation([[0, 7, 1, 6], [5, 2, 4, 3]]),
+              Permutation([[3, 6, 0, 5], [4, 1, 7, 2]]),
+              Permutation([[7, 4, 5], [1, 3, 0], [2], [6]]),
+              Permutation([[1, 3, 2], [7, 6, 5], [4], [0]]),
+              Permutation([[4, 7, 6], [2, 0, 3], [1], [5]]),
+              Permutation([[1, 2, 0], [4, 5, 6], [3], [7]]),
+              Permutation([[4, 2], [0, 6], [3, 7], [1, 5]]),
+              Permutation([[3, 5], [7, 1], [2, 6], [0, 4]]),
+              Permutation([[2, 5], [1, 6], [0, 4], [3, 7]]),
+              Permutation([[4, 3], [7, 0], [5, 1], [6, 2]]),
+              Permutation([[4, 1], [0, 5], [6, 2], [7, 3]]),
+              Permutation([[7, 2], [3, 6], [0, 4], [1, 5]]),
+              Permutation([0, 1, 2, 3, 4, 5, 6, 7])]
+    corners = tuple(symbols('A:H'))
+    faces = cube_faces
+    cube = Polyhedron(corners, faces, pgroup)
+
+    assert cube.edges == FiniteSet(*(
+        (0, 1), (6, 7), (1, 2), (5, 6), (0, 3), (2, 3),
+        (4, 7), (4, 5), (3, 7), (1, 5), (0, 4), (2, 6)))
+
+    for i in range(3):  # add 180 degree face rotations
+        cube.rotate(cube.pgroup[i]**2)
+
+    assert cube.corners == corners
+
+    for i in range(3, 7):  # add 240 degree axial corner rotations
+        cube.rotate(cube.pgroup[i]**2)
+
+    assert cube.corners == corners
+    cube.rotate(1)
+    raises(ValueError, lambda: cube.rotate(Permutation([0, 1])))
+    assert cube.corners != corners
+    assert cube.array_form == [7, 6, 4, 5, 3, 2, 0, 1]
+    assert cube.cyclic_form == [[0, 7, 1, 6], [2, 4, 3, 5]]
+    cube.reset()
+    assert cube.corners == corners
+
+    def check(h, size, rpt, target):
+
+        assert len(h.faces) + len(h.vertices) - len(h.edges) == 2
+        assert h.size == size
+
+        got = set()
+        for p in h.pgroup:
+            # make sure it restores original
+            P = h.copy()
+            hit = P.corners
+            for i in range(rpt):
+                P.rotate(p)
+                if P.corners == hit:
+                    break
+            else:
+                print('error in permutation', p.array_form)
+            for i in range(rpt):
+                P.rotate(p)
+                got.add(tuple(P.corners))
+                c = P.corners
+                f = [[c[i] for i in f] for f in P.faces]
+                assert h.faces == Polyhedron(c, f).faces
+        assert len(got) == target
+        assert PermutationGroup([Permutation(g) for g in got]).is_group
+
+    for h, size, rpt, target in zip(
+        (tetrahedron, square, octahedron, dodecahedron, icosahedron),
+        (4, 8, 6, 20, 12),
+        (3, 4, 4, 5, 5),
+            (12, 24, 24, 60, 60)):
+        check(h, size, rpt, target)
+
+
+def test_pgroups():
+    from sympy.combinatorics.polyhedron import (cube, tetrahedron_faces,
+            octahedron_faces, dodecahedron_faces, icosahedron_faces)
+    from sympy.combinatorics.polyhedron import _pgroup_calcs
+    (tetrahedron2, cube2, octahedron2, dodecahedron2, icosahedron2,
+     tetrahedron_faces2, cube_faces2, octahedron_faces2,
+     dodecahedron_faces2, icosahedron_faces2) = _pgroup_calcs()
+
+    assert tetrahedron == tetrahedron2
+    assert cube == cube2
+    assert octahedron == octahedron2
+    assert dodecahedron == dodecahedron2
+    assert icosahedron == icosahedron2
+    assert sorted(map(sorted, tetrahedron_faces)) == sorted(map(sorted, tetrahedron_faces2))
+    assert sorted(cube_faces) == sorted(cube_faces2)
+    assert sorted(octahedron_faces) == sorted(octahedron_faces2)
+    assert sorted(dodecahedron_faces) == sorted(dodecahedron_faces2)
+    assert sorted(icosahedron_faces) == sorted(icosahedron_faces2)

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_prufer.py

@@ -0,0 +1,74 @@
+from sympy.combinatorics.prufer import Prufer
+from sympy.testing.pytest import raises
+
+
+def test_prufer():
+    # number of nodes is optional
+    assert Prufer([[0, 1], [0, 2], [0, 3], [0, 4]], 5).nodes == 5
+    assert Prufer([[0, 1], [0, 2], [0, 3], [0, 4]]).nodes == 5
+
+    a = Prufer([[0, 1], [0, 2], [0, 3], [0, 4]])
+    assert a.rank == 0
+    assert a.nodes == 5
+    assert a.prufer_repr == [0, 0, 0]
+
+    a = Prufer([[2, 4], [1, 4], [1, 3], [0, 5], [0, 4]])
+    assert a.rank == 924
+    assert a.nodes == 6
+    assert a.tree_repr == [[2, 4], [1, 4], [1, 3], [0, 5], [0, 4]]
+    assert a.prufer_repr == [4, 1, 4, 0]
+
+    assert Prufer.edges([0, 1, 2, 3], [1, 4, 5], [1, 4, 6]) == \
+        ([[0, 1], [1, 2], [1, 4], [2, 3], [4, 5], [4, 6]], 7)
+    assert Prufer([0]*4).size == Prufer([6]*4).size == 1296
+
+    # accept iterables but convert to list of lists
+    tree = [(0, 1), (1, 5), (0, 3), (0, 2), (2, 6), (4, 7), (2, 4)]
+    tree_lists = [list(t) for t in tree]
+    assert Prufer(tree).tree_repr == tree_lists
+    assert sorted(Prufer(set(tree)).tree_repr) == sorted(tree_lists)
+
+    raises(ValueError, lambda: Prufer([[1, 2], [3, 4]]))  # 0 is missing
+    raises(ValueError, lambda: Prufer([[2, 3], [3, 4]]))  # 0, 1 are missing
+    assert Prufer(*Prufer.edges([1, 2], [3, 4])).prufer_repr == [1, 3]
+    raises(ValueError, lambda: Prufer.edges(
+        [1, 3], [3, 4]))  # a broken tree but edges doesn't care
+    raises(ValueError, lambda: Prufer.edges([1, 2], [5, 6]))
+    raises(ValueError, lambda: Prufer([[]]))
+
+    a = Prufer([[0, 1], [0, 2], [0, 3]])
+    b = a.next()
+    assert b.tree_repr == [[0, 2], [0, 1], [1, 3]]
+    assert b.rank == 1
+
+
+def test_round_trip():
+    def doit(t, b):
+        e, n = Prufer.edges(*t)
+        t = Prufer(e, n)
+        a = sorted(t.tree_repr)
+        b = [i - 1 for i in b]
+        assert t.prufer_repr == b
+        assert sorted(Prufer(b).tree_repr) == a
+        assert Prufer.unrank(t.rank, n).prufer_repr == b
+
+    doit([[1, 2]], [])
+    doit([[2, 1, 3]], [1])
+    doit([[1, 3, 2]], [3])
+    doit([[1, 2, 3]], [2])
+    doit([[2, 1, 4], [1, 3]], [1, 1])
+    doit([[3, 2, 1, 4]], [2, 1])
+    doit([[3, 2, 1], [2, 4]], [2, 2])
+    doit([[1, 3, 2, 4]], [3, 2])
+    doit([[1, 4, 2, 3]], [4, 2])
+    doit([[3, 1, 4, 2]], [4, 1])
+    doit([[4, 2, 1, 3]], [1, 2])
+    doit([[1, 2, 4, 3]], [2, 4])
+    doit([[1, 3, 4, 2]], [3, 4])
+    doit([[2, 4, 1], [4, 3]], [4, 4])
+    doit([[1, 2, 3, 4]], [2, 3])
+    doit([[2, 3, 1], [3, 4]], [3, 3])
+    doit([[1, 4, 3, 2]], [4, 3])
+    doit([[2, 1, 4, 3]], [1, 4])
+    doit([[2, 1, 3, 4]], [1, 3])
+    doit([[6, 2, 1, 4], [1, 3, 5, 8], [3, 7]], [1, 2, 1, 3, 3, 5])

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_rewriting.py

@@ -0,0 +1,49 @@
+from sympy.combinatorics.fp_groups import FpGroup
+from sympy.combinatorics.free_groups import free_group
+from sympy.testing.pytest import raises
+
+
+def test_rewriting():
+    F, a, b = free_group("a, b")
+    G = FpGroup(F, [a*b*a**-1*b**-1])
+    a, b = G.generators
+    R = G._rewriting_system
+    assert R.is_confluent
+
+    assert G.reduce(b**-1*a) == a*b**-1
+    assert G.reduce(b**3*a**4*b**-2*a) == a**5*b
+    assert G.equals(b**2*a**-1*b, b**4*a**-1*b**-1)
+
+    assert R.reduce_using_automaton(b*a*a**2*b**-1) == a**3
+    assert R.reduce_using_automaton(b**3*a**4*b**-2*a) == a**5*b
+    assert R.reduce_using_automaton(b**-1*a) == a*b**-1
+
+    G = FpGroup(F, [a**3, b**3, (a*b)**2])
+    R = G._rewriting_system
+    R.make_confluent()
+    # R._is_confluent should be set to True after
+    # a successful run of make_confluent
+    assert R.is_confluent
+    # but also the system should actually be confluent
+    assert R._check_confluence()
+    assert G.reduce(b*a**-1*b**-1*a**3*b**4*a**-1*b**-15) == a**-1*b**-1
+    # check for automaton reduction
+    assert R.reduce_using_automaton(b*a**-1*b**-1*a**3*b**4*a**-1*b**-15) == a**-1*b**-1
+
+    G = FpGroup(F, [a**2, b**3, (a*b)**4])
+    R = G._rewriting_system
+    assert G.reduce(a**2*b**-2*a**2*b) == b**-1
+    assert R.reduce_using_automaton(a**2*b**-2*a**2*b) == b**-1
+    assert G.reduce(a**3*b**-2*a**2*b) == a**-1*b**-1
+    assert R.reduce_using_automaton(a**3*b**-2*a**2*b) == a**-1*b**-1
+    # Check after adding a rule
+    R.add_rule(a**2, b)
+    assert R.reduce_using_automaton(a**2*b**-2*a**2*b) == b**-1
+    assert R.reduce_using_automaton(a**4*b**-2*a**2*b**3) == b
+
+    R.set_max(15)
+    raises(RuntimeError, lambda:  R.add_rule(a**-3, b))
+    R.set_max(20)
+    R.add_rule(a**-3, b)
+
+    assert R.add_rule(a, a) == set()

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_schur_number.py

@@ -0,0 +1,55 @@
+from sympy.core import S, Rational
+from sympy.combinatorics.schur_number import schur_partition, SchurNumber
+from sympy.core.random import _randint
+from sympy.testing.pytest import raises
+from sympy.core.symbol import symbols
+
+
+def _sum_free_test(subset):
+    """
+    Checks if subset is sum-free(There are no x,y,z in the subset such that
+    x + y = z)
+    """
+    for i in subset:
+        for j in subset:
+            assert (i + j in subset) is False
+
+
+def test_schur_partition():
+    raises(ValueError, lambda: schur_partition(S.Infinity))
+    raises(ValueError, lambda: schur_partition(-1))
+    raises(ValueError, lambda: schur_partition(0))
+    assert schur_partition(2) == [[1, 2]]
+
+    random_number_generator = _randint(1000)
+    for _ in range(5):
+        n = random_number_generator(1, 1000)
+        result = schur_partition(n)
+        t = 0
+        numbers = []
+        for item in result:
+            _sum_free_test(item)
+            """
+            Checks if the occurrence of all numbers is exactly one
+            """
+            t += len(item)
+            for l in item:
+                assert (l in numbers) is False
+                numbers.append(l)
+        assert n == t
+
+    x = symbols("x")
+    raises(ValueError, lambda: schur_partition(x))
+
+def test_schur_number():
+    first_known_schur_numbers = {1: 1, 2: 4, 3: 13, 4: 44, 5: 160}
+    for k in first_known_schur_numbers:
+        assert SchurNumber(k) == first_known_schur_numbers[k]
+
+    assert SchurNumber(S.Infinity) == S.Infinity
+    assert SchurNumber(0) == 0
+    raises(ValueError, lambda: SchurNumber(0.5))
+
+    n = symbols("n")
+    assert SchurNumber(n).lower_bound() == 3**n/2 - Rational(1, 2)
+    assert SchurNumber(8).lower_bound() == 5039

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_subsets.py

@@ -0,0 +1,63 @@
+from sympy.combinatorics.subsets import Subset, ksubsets
+from sympy.testing.pytest import raises
+
+
+def test_subset():
+    a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
+    assert a.next_binary() == Subset(['b'], ['a', 'b', 'c', 'd'])
+    assert a.prev_binary() == Subset(['c'], ['a', 'b', 'c', 'd'])
+    assert a.next_lexicographic() == Subset(['d'], ['a', 'b', 'c', 'd'])
+    assert a.prev_lexicographic() == Subset(['c'], ['a', 'b', 'c', 'd'])
+    assert a.next_gray() == Subset(['c'], ['a', 'b', 'c', 'd'])
+    assert a.prev_gray() == Subset(['d'], ['a', 'b', 'c', 'd'])
+    assert a.rank_binary == 3
+    assert a.rank_lexicographic == 14
+    assert a.rank_gray == 2
+    assert a.cardinality == 16
+    assert a.size == 2
+    assert Subset.bitlist_from_subset(a, ['a', 'b', 'c', 'd']) == '0011'
+
+    a = Subset([2, 5, 7], [1, 2, 3, 4, 5, 6, 7])
+    assert a.next_binary() == Subset([2, 5, 6], [1, 2, 3, 4, 5, 6, 7])
+    assert a.prev_binary() == Subset([2, 5], [1, 2, 3, 4, 5, 6, 7])
+    assert a.next_lexicographic() == Subset([2, 6], [1, 2, 3, 4, 5, 6, 7])
+    assert a.prev_lexicographic() == Subset([2, 5, 6, 7], [1, 2, 3, 4, 5, 6, 7])
+    assert a.next_gray() == Subset([2, 5, 6, 7], [1, 2, 3, 4, 5, 6, 7])
+    assert a.prev_gray() == Subset([2, 5], [1, 2, 3, 4, 5, 6, 7])
+    assert a.rank_binary == 37
+    assert a.rank_lexicographic == 93
+    assert a.rank_gray == 57
+    assert a.cardinality == 128
+
+    superset = ['a', 'b', 'c', 'd']
+    assert Subset.unrank_binary(4, superset).rank_binary == 4
+    assert Subset.unrank_gray(10, superset).rank_gray == 10
+
+    superset = [1, 2, 3, 4, 5, 6, 7, 8, 9]
+    assert Subset.unrank_binary(33, superset).rank_binary == 33
+    assert Subset.unrank_gray(25, superset).rank_gray == 25
+
+    a = Subset([], ['a', 'b', 'c', 'd'])
+    i = 1
+    while a.subset != Subset(['d'], ['a', 'b', 'c', 'd']).subset:
+        a = a.next_lexicographic()
+        i = i + 1
+    assert i == 16
+
+    i = 1
+    while a.subset != Subset([], ['a', 'b', 'c', 'd']).subset:
+        a = a.prev_lexicographic()
+        i = i + 1
+    assert i == 16
+
+    raises(ValueError, lambda: Subset(['a', 'b'], ['a']))
+    raises(ValueError, lambda: Subset(['a'], ['b', 'c']))
+    raises(ValueError, lambda: Subset.subset_from_bitlist(['a', 'b'], '010'))
+
+    assert Subset(['a'], ['a', 'b']) != Subset(['b'], ['a', 'b'])
+    assert Subset(['a'], ['a', 'b']) != Subset(['a'], ['a', 'c'])
+
+def test_ksubsets():
+    assert list(ksubsets([1, 2, 3], 2)) == [(1, 2), (1, 3), (2, 3)]
+    assert list(ksubsets([1, 2, 3, 4, 5], 2)) == [(1, 2), (1, 3), (1, 4),
+               (1, 5), (2, 3), (2, 4), (2, 5), (3, 4), (3, 5), (4, 5)]

llmeval-env/lib/python3.10/site-packages/sympy/combinatorics/tests/test_testutil.py

@@ -0,0 +1,55 @@
+from sympy.combinatorics.named_groups import SymmetricGroup, AlternatingGroup,\
+    CyclicGroup
+from sympy.combinatorics.testutil import _verify_bsgs, _cmp_perm_lists,\
+    _naive_list_centralizer, _verify_centralizer,\
+    _verify_normal_closure
+from sympy.combinatorics.permutations import Permutation
+from sympy.combinatorics.perm_groups import PermutationGroup
+from sympy.core.random import shuffle
+
+
+def test_cmp_perm_lists():
+    S = SymmetricGroup(4)
+    els = list(S.generate_dimino())
+    other = els[:]
+    shuffle(other)
+    assert _cmp_perm_lists(els, other) is True
+
+
+def test_naive_list_centralizer():
+    # verified by GAP
+    S = SymmetricGroup(3)
+    A = AlternatingGroup(3)
+    assert _naive_list_centralizer(S, S) == [Permutation([0, 1, 2])]
+    assert PermutationGroup(_naive_list_centralizer(S, A)).is_subgroup(A)
+
+
+def test_verify_bsgs():
+    S = SymmetricGroup(5)
+    S.schreier_sims()
+    base = S.base
+    strong_gens = S.strong_gens
+    assert _verify_bsgs(S, base, strong_gens) is True
+    assert _verify_bsgs(S, base[:-1], strong_gens) is False
+    assert _verify_bsgs(S, base, S.generators) is False
+
+
+def test_verify_centralizer():
+    # verified by GAP
+    S = SymmetricGroup(3)
+    A = AlternatingGroup(3)
+    triv = PermutationGroup([Permutation([0, 1, 2])])
+    assert _verify_centralizer(S, S, centr=triv)
+    assert _verify_centralizer(S, A, centr=A)
+
+
+def test_verify_normal_closure():
+    # verified by GAP
+    S = SymmetricGroup(3)
+    A = AlternatingGroup(3)
+    assert _verify_normal_closure(S, A, closure=A)
+    S = SymmetricGroup(5)
+    A = AlternatingGroup(5)
+    C = CyclicGroup(5)
+    assert _verify_normal_closure(S, A, closure=A)
+    assert _verify_normal_closure(S, C, closure=A)

llmeval-env/lib/python3.10/site-packages/sympy/logic/__init__.py

@@ -0,0 +1,12 @@
+from .boolalg import (to_cnf, to_dnf, to_nnf, And, Or, Not, Xor, Nand, Nor, Implies,
+    Equivalent, ITE, POSform, SOPform, simplify_logic, bool_map, true, false,
+    gateinputcount)
+from .inference import satisfiable
+
+__all__ = [
+    'to_cnf', 'to_dnf', 'to_nnf', 'And', 'Or', 'Not', 'Xor', 'Nand', 'Nor',
+    'Implies', 'Equivalent', 'ITE', 'POSform', 'SOPform', 'simplify_logic',
+    'bool_map', 'true', 'false', 'gateinputcount',
+
+    'satisfiable',
+]

llmeval-env/lib/python3.10/site-packages/sympy/logic/algorithms/dpll.py

@@ -0,0 +1,308 @@
+"""Implementation of DPLL algorithm
+
+Further improvements: eliminate calls to pl_true, implement branching rules,
+efficient unit propagation.
+
+References:
+  - https://en.wikipedia.org/wiki/DPLL_algorithm
+  - https://www.researchgate.net/publication/242384772_Implementations_of_the_DPLL_Algorithm
+"""
+
+from sympy.core.sorting import default_sort_key
+from sympy.logic.boolalg import Or, Not, conjuncts, disjuncts, to_cnf, \
+    to_int_repr, _find_predicates
+from sympy.assumptions.cnf import CNF
+from sympy.logic.inference import pl_true, literal_symbol
+
+
+def dpll_satisfiable(expr):
+    """
+    Check satisfiability of a propositional sentence.
+    It returns a model rather than True when it succeeds
+
+    >>> from sympy.abc import A, B
+    >>> from sympy.logic.algorithms.dpll import dpll_satisfiable
+    >>> dpll_satisfiable(A & ~B)
+    {A: True, B: False}
+    >>> dpll_satisfiable(A & ~A)
+    False
+
+    """
+    if not isinstance(expr, CNF):
+        clauses = conjuncts(to_cnf(expr))
+    else:
+        clauses = expr.clauses
+    if False in clauses:
+        return False
+    symbols = sorted(_find_predicates(expr), key=default_sort_key)
+    symbols_int_repr = set(range(1, len(symbols) + 1))
+    clauses_int_repr = to_int_repr(clauses, symbols)
+    result = dpll_int_repr(clauses_int_repr, symbols_int_repr, {})
+    if not result:
+        return result
+    output = {}
+    for key in result:
+        output.update({symbols[key - 1]: result[key]})
+    return output
+
+
+def dpll(clauses, symbols, model):
+    """
+    Compute satisfiability in a partial model.
+    Clauses is an array of conjuncts.
+
+    >>> from sympy.abc import A, B, D
+    >>> from sympy.logic.algorithms.dpll import dpll
+    >>> dpll([A, B, D], [A, B], {D: False})
+    False
+
+    """
+    # compute DP kernel
+    P, value = find_unit_clause(clauses, model)
+    while P:
+        model.update({P: value})
+        symbols.remove(P)
+        if not value:
+            P = ~P
+        clauses = unit_propagate(clauses, P)
+        P, value = find_unit_clause(clauses, model)
+    P, value = find_pure_symbol(symbols, clauses)
+    while P:
+        model.update({P: value})
+        symbols.remove(P)
+        if not value:
+            P = ~P
+        clauses = unit_propagate(clauses, P)
+        P, value = find_pure_symbol(symbols, clauses)
+    # end DP kernel
+    unknown_clauses = []
+    for c in clauses:
+        val = pl_true(c, model)
+        if val is False:
+            return False
+        if val is not True:
+            unknown_clauses.append(c)
+    if not unknown_clauses:
+        return model
+    if not clauses:
+        return model
+    P = symbols.pop()
+    model_copy = model.copy()
+    model.update({P: True})
+    model_copy.update({P: False})
+    symbols_copy = symbols[:]
+    return (dpll(unit_propagate(unknown_clauses, P), symbols, model) or
+            dpll(unit_propagate(unknown_clauses, Not(P)), symbols_copy, model_copy))
+
+
+def dpll_int_repr(clauses, symbols, model):
+    """
+    Compute satisfiability in a partial model.
+    Arguments are expected to be in integer representation
+
+    >>> from sympy.logic.algorithms.dpll import dpll_int_repr
+    >>> dpll_int_repr([{1}, {2}, {3}], {1, 2}, {3: False})
+    False
+
+    """
+    # compute DP kernel
+    P, value = find_unit_clause_int_repr(clauses, model)
+    while P:
+        model.update({P: value})
+        symbols.remove(P)
+        if not value:
+            P = -P
+        clauses = unit_propagate_int_repr(clauses, P)
+        P, value = find_unit_clause_int_repr(clauses, model)
+    P, value = find_pure_symbol_int_repr(symbols, clauses)
+    while P:
+        model.update({P: value})
+        symbols.remove(P)
+        if not value:
+            P = -P
+        clauses = unit_propagate_int_repr(clauses, P)
+        P, value = find_pure_symbol_int_repr(symbols, clauses)
+    # end DP kernel
+    unknown_clauses = []
+    for c in clauses:
+        val = pl_true_int_repr(c, model)
+        if val is False:
+            return False
+        if val is not True:
+            unknown_clauses.append(c)
+    if not unknown_clauses:
+        return model
+    P = symbols.pop()
+    model_copy = model.copy()
+    model.update({P: True})
+    model_copy.update({P: False})
+    symbols_copy = symbols.copy()
+    return (dpll_int_repr(unit_propagate_int_repr(unknown_clauses, P), symbols, model) or
+            dpll_int_repr(unit_propagate_int_repr(unknown_clauses, -P), symbols_copy, model_copy))
+
+### helper methods for DPLL
+
+
+def pl_true_int_repr(clause, model={}):
+    """
+    Lightweight version of pl_true.
+    Argument clause represents the set of args of an Or clause. This is used
+    inside dpll_int_repr, it is not meant to be used directly.
+
+    >>> from sympy.logic.algorithms.dpll import pl_true_int_repr
+    >>> pl_true_int_repr({1, 2}, {1: False})
+    >>> pl_true_int_repr({1, 2}, {1: False, 2: False})
+    False
+
+    """
+    result = False
+    for lit in clause:
+        if lit < 0:
+            p = model.get(-lit)
+            if p is not None:
+                p = not p
+        else:
+            p = model.get(lit)
+        if p is True:
+            return True
+        elif p is None:
+            result = None
+    return result
+
+
+def unit_propagate(clauses, symbol):
+    """
+    Returns an equivalent set of clauses
+    If a set of clauses contains the unit clause l, the other clauses are
+    simplified by the application of the two following rules:
+
+      1. every clause containing l is removed
+      2. in every clause that contains ~l this literal is deleted
+
+    Arguments are expected to be in CNF.
+
+    >>> from sympy.abc import A, B, D
+    >>> from sympy.logic.algorithms.dpll import unit_propagate
+    >>> unit_propagate([A | B, D | ~B, B], B)
+    [D, B]
+
+    """
+    output = []
+    for c in clauses:
+        if c.func != Or:
+            output.append(c)
+            continue
+        for arg in c.args:
+            if arg == ~symbol:
+                output.append(Or(*[x for x in c.args if x != ~symbol]))
+                break
+            if arg == symbol:
+                break
+        else:
+            output.append(c)
+    return output
+
+
+def unit_propagate_int_repr(clauses, s):
+    """
+    Same as unit_propagate, but arguments are expected to be in integer
+    representation
+
+    >>> from sympy.logic.algorithms.dpll import unit_propagate_int_repr
+    >>> unit_propagate_int_repr([{1, 2}, {3, -2}, {2}], 2)
+    [{3}]
+
+    """
+    negated = {-s}
+    return [clause - negated for clause in clauses if s not in clause]
+
+
+def find_pure_symbol(symbols, unknown_clauses):
+    """
+    Find a symbol and its value if it appears only as a positive literal
+    (or only as a negative) in clauses.
+
+    >>> from sympy.abc import A, B, D
+    >>> from sympy.logic.algorithms.dpll import find_pure_symbol
+    >>> find_pure_symbol([A, B, D], [A|~B,~B|~D,D|A])
+    (A, True)
+
+    """
+    for sym in symbols:
+        found_pos, found_neg = False, False
+        for c in unknown_clauses:
+            if not found_pos and sym in disjuncts(c):
+                found_pos = True
+            if not found_neg and Not(sym) in disjuncts(c):
+                found_neg = True
+        if found_pos != found_neg:
+            return sym, found_pos
+    return None, None
+
+
+def find_pure_symbol_int_repr(symbols, unknown_clauses):
+    """
+    Same as find_pure_symbol, but arguments are expected
+    to be in integer representation
+
+    >>> from sympy.logic.algorithms.dpll import find_pure_symbol_int_repr
+    >>> find_pure_symbol_int_repr({1,2,3},
+    ...     [{1, -2}, {-2, -3}, {3, 1}])
+    (1, True)
+
+    """
+    all_symbols = set().union(*unknown_clauses)
+    found_pos = all_symbols.intersection(symbols)
+    found_neg = all_symbols.intersection([-s for s in symbols])
+    for p in found_pos:
+        if -p not in found_neg:
+            return p, True
+    for p in found_neg:
+        if -p not in found_pos:
+            return -p, False
+    return None, None
+
+
+def find_unit_clause(clauses, model):
+    """
+    A unit clause has only 1 variable that is not bound in the model.
+
+    >>> from sympy.abc import A, B, D
+    >>> from sympy.logic.algorithms.dpll import find_unit_clause
+    >>> find_unit_clause([A | B | D, B | ~D, A | ~B], {A:True})
+    (B, False)
+
+    """
+    for clause in clauses:
+        num_not_in_model = 0
+        for literal in disjuncts(clause):
+            sym = literal_symbol(literal)
+            if sym not in model:
+                num_not_in_model += 1
+                P, value = sym, not isinstance(literal, Not)
+        if num_not_in_model == 1:
+            return P, value
+    return None, None
+
+
+def find_unit_clause_int_repr(clauses, model):
+    """
+    Same as find_unit_clause, but arguments are expected to be in
+    integer representation.
+
+    >>> from sympy.logic.algorithms.dpll import find_unit_clause_int_repr
+    >>> find_unit_clause_int_repr([{1, 2, 3},
+    ...     {2, -3}, {1, -2}], {1: True})
+    (2, False)
+
+    """
+    bound = set(model) | {-sym for sym in model}
+    for clause in clauses:
+        unbound = clause - bound
+        if len(unbound) == 1:
+            p = unbound.pop()
+            if p < 0:
+                return -p, False
+            else:
+                return p, True
+    return None, None