| { | |
| "paper_id": "C92-1022", | |
| "header": { | |
| "generated_with": "S2ORC 1.0.0", | |
| "date_generated": "2023-01-19T12:34:42.912906Z" | |
| }, | |
| "title": "Chart Parsing of Robust Grmnmars *", | |
| "authors": [ | |
| { | |
| "first": "Sebastian", | |
| "middle": [], | |
| "last": "Goeser", | |
| "suffix": "", | |
| "affiliation": {}, | |
| "email": "" | |
| }, | |
| { | |
| "first": "Ibm", | |
| "middle": [], | |
| "last": "Deutschland Gmbh", | |
| "suffix": "", | |
| "affiliation": {}, | |
| "email": "" | |
| }, | |
| { | |
| "first": "Hans-Klemm-Str", | |
| "middle": [], | |
| "last": "Gadl", | |
| "suffix": "", | |
| "affiliation": {}, | |
| "email": "" | |
| }, | |
| { | |
| "first": "D-7030", | |
| "middle": [], | |
| "last": "Bfblingen", | |
| "suffix": "", | |
| "affiliation": {}, | |
| "email": "" | |
| } | |
| ], | |
| "year": "", | |
| "venue": null, | |
| "identifiers": {}, | |
| "abstract": "", | |
| "pdf_parse": { | |
| "paper_id": "C92-1022", | |
| "_pdf_hash": "", | |
| "abstract": [], | |
| "body_text": [ | |
| { | |
| "text": "Robustness is a formal behaviour of natural langatage grammars to assign a best partial description to linguistic events wltose strong description is inconsistent or cannot be constructed. Events of this sort may be called defective with respect to a grammar fragment. Defectiveness arises from the performance use that hnman beings make of language. Since defectiveness can be seen as failure of linguistic description, the principal way to robustness is a method to weaken these descriptions.", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Introduction", | |
| "sec_num": "1" | |
| }, | |
| { | |
| "text": "Robust parsing, then, is parsing of robust granmmrs: a parser is robust iff it has the capabillty to interpret weak grammar fraKments correctly. In this paper, I shall try to substantiate this claim by motivating a grammar dependent approach to robust parsing and then describing a chart parsing nlgoritbra for ro~ bust g ......... rs. Though only c(ontext) f(ree) grammars will be adressed, there is an obvious extension of the algorithm to annotated (unification-) grammars (WACSG formalism, see Goeser 1900 ) along the lines of (Shieber 198~ ).", | |
| "cite_spans": [ | |
| { | |
| "start": 498, | |
| "end": 509, | |
| "text": "Goeser 1900", | |
| "ref_id": null | |
| }, | |
| { | |
| "start": 531, | |
| "end": 544, | |
| "text": "(Shieber 198~", | |
| "ref_id": null | |
| } | |
| ], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Introduction", | |
| "sec_num": "1" | |
| }, | |
| { | |
| "text": "Grammar based robustness tools have been explored in a variety of formalisms, e.g. the metarule device within the ATN formalism (Weischedel and Sondheimer 1898), entity data structures in a case frame approach (Hayes 1984) or the weak description approach in unification based grammars (Kudo et al. 1988 , Goeser 1990 ). Parsing cf grammars with ro-\u00b0The work reported has been done while the author received an LGF grnnt at the University of Stuttgart. bustness features competes with algorithnfic approaches to robustness where parsing algorithms, (usually chart parsers except in Tomabechi and Tomita (1988) where LR(k) parsing is advocated) are extended to inelude robustness features (Mellish 1989 , Long 1988 ) and/or heuristics to handle defect cases (Banger 1990 , Stock et al. 1988 ).", | |
| "cite_spans": [ | |
| { | |
| "start": 210, | |
| "end": 222, | |
| "text": "(Hayes 1984)", | |
| "ref_id": "BIBREF5" | |
| }, | |
| { | |
| "start": 286, | |
| "end": 303, | |
| "text": "(Kudo et al. 1988", | |
| "ref_id": null | |
| }, | |
| { | |
| "start": 304, | |
| "end": 317, | |
| "text": ", Goeser 1990", | |
| "ref_id": "BIBREF3" | |
| }, | |
| { | |
| "start": 582, | |
| "end": 609, | |
| "text": "Tomabechi and Tomita (1988)", | |
| "ref_id": "BIBREF13" | |
| }, | |
| { | |
| "start": 688, | |
| "end": 701, | |
| "text": "(Mellish 1989", | |
| "ref_id": null | |
| }, | |
| { | |
| "start": 702, | |
| "end": 713, | |
| "text": ", Long 1988", | |
| "ref_id": null | |
| }, | |
| { | |
| "start": 757, | |
| "end": 769, | |
| "text": "(Banger 1990", | |
| "ref_id": null | |
| }, | |
| { | |
| "start": 770, | |
| "end": 789, | |
| "text": ", Stock et al. 1988", | |
| "ref_id": "BIBREF12" | |
| } | |
| ], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Introduction", | |
| "sec_num": "1" | |
| }, | |
| { | |
| "text": "Maybe the most critical issue in robust parsing is ambigatity, which emerges when constituency is loosened to some cf substring analysis. E.g. Mellish (1989) p ..... for a cfg G the (cf) set PAR(G) which is the set of all strings contain~ ing a sequence ofnonempty substrings which is in the cflangqtage L(G) I In the worst case scenario where all these seqaences are in L(G), we get for a w E L(G) with an ambiguity k (in G) an exponential ambiguity of k x 2 I'1 as mx upper bound. Even in a non-worst cast, which should be the case of realistic cfgs, local ambiguities from substring analysis massively increase parsing time. E.g. in the (non-defective) example 1, the arcs a, b, c are empirically valid while the arcs d,e are artefacts of m~ algorithm parsing PAR(G).", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Introduction", | |
| "sec_num": "1" | |
| }, | |
| { | |
| "text": "1See Goeser (1990) SET indexed item or by the predictor relation.", | |
| "cite_spans": [ | |
| { | |
| "start": 5, | |
| "end": 18, | |
| "text": "Goeser (1990)", | |
| "ref_id": "BIBREF3" | |
| } | |
| ], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Introduction", | |
| "sec_num": "1" | |
| }, | |
| { | |
| "text": "~illCe tile scanller conlponellt lIIS~v ~-)e been as n lexical case of the completer, )h~ RPSG algorithm could be reduced to a single active completer component and the controlling relation D (Kilbury 1985) . Remark thai the scannet allows for IIPSG rules with RtlS strings of terminals and non-terminMs. A partial lookshead of 1, being applied to active items only, has proven advantageous in the basic variant (DSrre 1987). lu the RPSG variant, the length of the lookahead must be conditioned to the fact that zero or more non-derived but generated words may follow a given vertex. The lookahead fails if, for the first To-Parse sym-", | |
| "cite_spans": [ | |
| { | |
| "start": 192, | |
| "end": 206, | |
| "text": "(Kilbury 1985)", | |
| "ref_id": "BIBREF6" | |
| } | |
| ], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Scanner and Lookahead", | |
| "sec_num": "4.4" | |
| }, | |
| { | |
| "text": "The relation F il~cludes the operation ~) which procedura)ly asserts new items 2o the chrttt bol, there is no first derivable lexical item, that is accessible given the actual substring information.", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Scanner and Lookahead", | |
| "sec_num": "4.4" | |
| }, | |
| { | |
| "text": "Unfortunately, the scanner is not independent from this lookahead, since, in many cases, the item licensed by a lookahead operation onto o lexical item i is exactly the item licensing i within the predictor relation. That is, from a procedural viewpoint of enterlng items into the chart, the lookahead condition and the predictor block each other for certain lcxical items. In this situation we decided to have a scanner without a predictor relation, thus paying for lookahead with an increased local lexical ambiguity.", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Scanner and Lookahead", | |
| "sec_num": "4.4" | |
| }, | |
| { | |
| "text": "The algorithm described has been implemented and tested as part of the WACSG system that is based on the Stuttgart LFG system (Eisele 1987).", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Status and Conclusion", | |
| "sec_num": "5" | |
| }, | |
| { | |
| "text": "Chart parsing of robust cf gzammars is a powerful method to cope with the confignrational aspects of defectiveness. It is part of a major enterprise to re-analyze robustness not as o parsing problem but as a problem of weak linguistic description. Therefore, any formal work on the linguistics of defectiveness can be expected to improve our methods of robust parsing.", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Status and Conclusion", | |
| "sec_num": "5" | |
| } | |
| ], | |
| "back_matter": [ | |
| { | |
| "text": "Algorithm: An RPSG Chart Parser Input:1. RPSG G =< Caq.a, Lez, P, Sseti.~ ", | |
| "cite_spans": [], | |
| "ref_spans": [], | |
| "eq_spans": [], | |
| "section": "Appendix", | |
| "sec_num": null | |
| } | |
| ], | |
| "bib_entries": { | |
| "BIBREF0": { | |
| "ref_id": "b0", | |
| "title": "Recovery Strategies for Parsing Extragrammatica] Language", | |
| "authors": [ | |
| { | |
| "first": "J", | |
| "middle": [], | |
| "last": "Carboncll", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "P", | |
| "middle": [], | |
| "last": "Hayes", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1983, | |
| "venue": "", | |
| "volume": "9", | |
| "issue": "", | |
| "pages": "3--4", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Carboncll, J. and Hayes, P.: Recovery Strategies for Parsing Extragrammatica] Language, in: AJCL 9, 3-4, 1983", | |
| "links": null | |
| }, | |
| "BIBREF1": { | |
| "ref_id": "b1", | |
| "title": "Wcitcrentwicklung des Earley-Algorithmus flit kontextfreie and ID/LP-Graanmatiken", | |
| "authors": [ | |
| { | |
| "first": "Rre", | |
| "middle": [], | |
| "last": "D~", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "J", | |
| "middle": [], | |
| "last": "", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1987, | |
| "venue": "LiLog-Report", | |
| "volume": "28", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "D~,rre, J.: Wcitcrentwicklung des Earley- Algorithmus flit kontextfreie and ID/LP- Graanmatiken, LiLog-Report 28, IBM Deutschland 1987", | |
| "links": null | |
| }, | |
| "BIBREF2": { | |
| "ref_id": "b2", | |
| "title": "An Efficient Context-free Parsing Algorithm", | |
| "authors": [ | |
| { | |
| "first": "J", | |
| "middle": [], | |
| "last": "Earley", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1970, | |
| "venue": "CACM 13", | |
| "volume": "2", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Earley, J.: An Efficient Context-free Pars- ing Algorithm, in: CACM 13, 2, 1970", | |
| "links": null | |
| }, | |
| "BIBREF3": { | |
| "ref_id": "b3", | |
| "title": "A linguistic Theory of Robusthess", | |
| "authors": [ | |
| { | |
| "first": "S", | |
| "middle": [], | |
| "last": "Goeser", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1990, | |
| "venue": "Proc. of COLING-13", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Goeser, S.: A linguistic Theory of Robust- hess, in: Proc. of COLING-13, Helsinki 1990", | |
| "links": null | |
| }, | |
| "BIBREF4": { | |
| "ref_id": "b4", | |
| "title": "Eine linguistische Theorie der Robustheit", | |
| "authors": [ | |
| { | |
| "first": "S", | |
| "middle": [], | |
| "last": "Goescr", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1991, | |
| "venue": "", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Goescr, S.: Eine linguistische Theorie der Robustheit, Konstanz 1991", | |
| "links": null | |
| }, | |
| "BIBREF5": { | |
| "ref_id": "b5", | |
| "title": "Entity-Oriented Parsing", | |
| "authors": [ | |
| { | |
| "first": "P", | |
| "middle": [ | |
| "J" | |
| ], | |
| "last": "Hayes", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1984, | |
| "venue": "COLING-1O", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Hayes, P.J.: Entity-Oriented Parsing, in: COLING-1O, Stanford 1984", | |
| "links": null | |
| }, | |
| "BIBREF6": { | |
| "ref_id": "b6", | |
| "title": "Chart Parsing and the Earley algorithm", | |
| "authors": [ | |
| { | |
| "first": "J", | |
| "middle": [], | |
| "last": "Kilbury", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1985, | |
| "venue": "Kontextfreie Syntaxen und verwandte Systeme", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Kilbury, J.: Chart Parsing and the Ear- ley algorithm, in: Klenk, U. (ed.): Kon- textfreie Syntaxen und verwandte Sys- teme, Max Niemeyer, Tiibingen 1985", | |
| "links": null | |
| }, | |
| "BIBREF7": { | |
| "ref_id": "b7", | |
| "title": "Relax~tlolt Techniques for Parsing Grammatically m-Formed Input", | |
| "authors": [ | |
| { | |
| "first": "S", | |
| "middle": [ | |
| "C" | |
| ], | |
| "last": "Kwasny", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "N", | |
| "middle": [ | |
| "K" | |
| ], | |
| "last": "Sondhcimer", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1981, | |
| "venue": "", | |
| "volume": "7", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Kwasny, S.C. and and Sondhcimer, N.K.: Relax~tlolt Techniques for Pars- ing Grammatically m-Formed Input, in: AJCL 7,2, 1981", | |
| "links": null | |
| }, | |
| "BIBREF8": { | |
| "ref_id": "b8", | |
| "title": "Parsing Incomplete Sentences", | |
| "authors": [ | |
| { | |
| "first": "B", | |
| "middle": [], | |
| "last": "Lung", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1988, | |
| "venue": "Proc. COLING-12", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Lung, B.: Parsing Incomplete Sentences, in: Proc. COLING-12, Budapest 1988", | |
| "links": null | |
| }, | |
| "BIBREF9": { | |
| "ref_id": "b9", | |
| "title": "Parsing Spoken Language", | |
| "authors": [ | |
| { | |
| "first": "H", | |
| "middle": [], | |
| "last": "Langer", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1990, | |
| "venue": "Proc. COLING-13", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Langer, H.: Parsing Spoken Language, in: Proc. COLING-13, Helsinki 1990", | |
| "links": null | |
| }, | |
| "BIBREF10": { | |
| "ref_id": "b10", | |
| "title": "Some Chart-Based Techniques for parsing HI-formed Input", | |
| "authors": [ | |
| { | |
| "first": "C", | |
| "middle": [ | |
| "S" | |
| ], | |
| "last": "Mcllish", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1987, | |
| "venue": "Proc. ACL 27", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Mcllish, C.S.: Some Chart-Based Tech- niques for parsing HI-formed Input, in: Proc. ACL 27, V~mcouver 1987", | |
| "links": null | |
| }, | |
| "BIBREF11": { | |
| "ref_id": "b11", | |
| "title": "Using Restriction to Extend Parsing Algorithms for Complex Feature Based Formalisms", | |
| "authors": [ | |
| { | |
| "first": "S", | |
| "middle": [ | |
| "M" | |
| ], | |
| "last": "Shieber", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1985, | |
| "venue": "Proc. ACL", | |
| "volume": "25", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Shieber, S.M.: Using Restriction to Ex- tend Parsing Algorithms for Complex Feature Based Formalisms, in: Proc. ACL 25, 1985", | |
| "links": null | |
| }, | |
| "BIBREF12": { | |
| "ref_id": "b12", | |
| "title": "Island Parsing and Bidirectional Charts", | |
| "authors": [ | |
| { | |
| "first": "I$]", | |
| "middle": [], | |
| "last": "Stock", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "O", | |
| "middle": [], | |
| "last": "Falcone", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "R", | |
| "middle": [], | |
| "last": "Inslmnamo", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "P", | |
| "middle": [], | |
| "last": "", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1988, | |
| "venue": "Proc. COLING 12", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "[I$] Stock, O., Falcone, R, Inslmnamo, P.: Is- land Parsing and Bidirectional Charts, in: Proc. COLING 12, Budapest 1988", | |
| "links": null | |
| }, | |
| "BIBREF13": { | |
| "ref_id": "b13", | |
| "title": "The Integration of Unificotion-B~sed Pragmatics for Real-Time Understanding of Noisy Continuous Speech Input", | |
| "authors": [ | |
| { | |
| "first": "H", | |
| "middle": [], | |
| "last": "Tomabechi", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "M", | |
| "middle": [], | |
| "last": "Tomita", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1988, | |
| "venue": "", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Tomabechi, H. and Tomita,M.: The In- tegration of Unificotion-B~sed Pragmat- ics for Real-Time Understanding of Noisy Continuous Speech Input, in: Proe. AAAI 7, Saint Panl 1988.", | |
| "links": null | |
| }, | |
| "BIBREF14": { | |
| "ref_id": "b14", | |
| "title": "A machlne-readable corpus of spoken language from psychotherapeutic discourse", | |
| "authors": [ | |
| { | |
| "first": "", | |
| "middle": [], | |
| "last": "Ulmer Textbank", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": null, | |
| "venue": "", | |
| "volume": "", | |
| "issue": "", | |
| "pages": "", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "ULMER TEXTBANK: A machlne-readable corpus of spoken lan- guage from psychotherapeutic discourse, University of Uhn", | |
| "links": null | |
| }, | |
| "BIBREF15": { | |
| "ref_id": "b15", | |
| "title": "Metarules as n Basis for Processing HI-Formed Input", | |
| "authors": [ | |
| { | |
| "first": "R", | |
| "middle": [ | |
| "M" | |
| ], | |
| "last": "Weischedel", | |
| "suffix": "" | |
| }, | |
| { | |
| "first": "N", | |
| "middle": [ | |
| "K" | |
| ], | |
| "last": "Sondhelmer", | |
| "suffix": "" | |
| } | |
| ], | |
| "year": 1983, | |
| "venue": "", | |
| "volume": "9", | |
| "issue": "", | |
| "pages": "3--4", | |
| "other_ids": {}, | |
| "num": null, | |
| "urls": [], | |
| "raw_text": "Weischedel, R.M. and Sondhelmer, N.K.: Metarules as n Basis for Processing HI- Formed Input, in: AJCL 9, 3-4, 1983", | |
| "links": null | |
| } | |
| }, | |
| "ref_entries": { | |
| "FIGREF0": { | |
| "type_str": "figure", | |
| "text": "=Peter':elf~'~ den Peter ~gefaellt --A'interessiert die Schule sehr [TD ] 3S E b'set.,a tle.*(S, ,,,\u00b0';A,~) = 1 ^ where c~,fl,,g \u00a2 (~,,.~)\"4.2 The PredictorThe predictor of the RPSG variant s is, again, a relation over vertices and nou-ternfinals. ]ha contrast to the basis variant, however, a null predictor would be incorrect for the RPSG variant, since the acceptance of a string now depends on the substring information percolated by lhc predictor. The. first predictor clause allows an \"initialisation\" for every vertex. The second clause formulates the expectation of a non-terminal A, I by an active item i.e. an item with a nonempty llst To-Parse, and the tltird the expectation by passive items with a SET index. Clause 4 expects a start synd)ol on the basis of left adjunction to a SET indexed symbol. The following proposition, a proof of wbid~ is available from the anthor, states the correctness of this predictor formalization..\u00a2en * ( S, ,o \"'~ A,~g ) = 1 iff D ( i, A,, )for a S E Sseti,,,l4.~ The CompleterThe completer component integrates the predictor relation and the substring generation function and has two rules for rightside and ~see Appendix A for a complete formal characteri-t~ation of the RPSG chart parser leftside mljunction under a set-indexed symbol. Given that the conditions in the if-clause (and the lookahead condition, see below) yield, tlte completer adds new items to the chart 9 Clansc I of the RPSG completer, is, up to the generation function instead of derivation, equivalent to the completer of the basis vari-t~nt: Given a rightslde passive item, it adds a new item both for a matching active item and for the prediction of an appropriate rules's LtlS symbol. Tltus, no cyclic items have to be created. Furthermore, since RPSGs do not have productions, there is no need to handle cyclic items at all. Clause 2 does riglitsld-ndjnnclion of a start symbol item to a passive SET indexed item. ]ht left a~unction according to clause 3, the adjoined (passive) item can again be licensed both by another (active or passive)", | |
| "uris": null, | |
| "num": null | |
| }, | |
| "TABREF0": { | |
| "content": "<table><tr><td>(i)</td><td/><td/><td colspan=\"3\">(see e.g, example (3)) ~</td></tr><tr><td/><td/><td>S(|</td><td colspan=\"3\">(2) da [TD ] ~SE Sset S -*~ wO'~A~ A [is es d ....... dt ein A</td></tr><tr><td colspan=\"2\">Peter</td><td>\u2022 1</td><td colspan=\"3\">there [ is it then still a [BU ] ~ ~ ~,-~</td><td>A</td></tr><tr><td colspan=\"3\">abrings tat2 b I</td><td colspan=\"3\">comes yet another problem to-that] kmnmt noch ein anderes Problem hinzu] where ~5 ~ V ~</td></tr><tr><td>nice</td><td/><td>\"4</td><td>4</td><td>The RPSG</td><td>variant</td></tr><tr><td>gift to 3</td><td colspan=\"2\">,~ es Basic algorithm</td><td colspan=\"3\">(3) der Peter [ hat konnte das dieses deshalb the Peter [ has could the this therefore 4.1 Item Concept</td></tr><tr><td colspan=\"3\">As a parsing algorithm to start from, Earley's A Mary \u00aer</td><td colspan=\"3\">ehemaligen Lieferwagen h~ the RPSG variant, items are represertted as former truck PROLOG facts</td></tr><tr><td colspan=\"3\">Reflecting syntactic defectiveness in a cfg metros to n-~sigqt it a coxtfigtlrational regular-</td><td colspan=\"3\">A hat das gekauft] item( lumber, Lind, Rirtd, LRS, ,.4 has it bought] Pazsod, To_Parso~ RofList)</td></tr><tr><td colspan=\"3\">Sty. Obviously, there is syntactic defectivity</td><td/><td/></tr><tr><td colspan=\"3\">which is syntactically nonregalar, such as cor-raq~ted output from a speech recognition de-</td><td colspan=\"3\">2 lteeursive partial string</td></tr><tr><td colspan=\"3\">vice (Tomabechi and Tomita 1988) ~ or global</td><td/><td/></tr><tr><td colspan=\"3\">constituent breaks (Goeser 1991), which can fonowing predictor be subjected to syntactic prefix analysis only. On the other hand, there are spoken language concept:</td><td/><td/></tr><tr><td colspan=\"3\">constructions (Lindgren 1987, Goeser 1991, * the predictor is a relation D(i,A) C Langer 1990) and various kinds of \"fragmen-n + x C, al between a vertex i < n and tary utterances\" (Cnrbonell and ltnyes 1983) a rtort-termirtal .,4. It is integrated into that definitively show configurational proper-the completer and scanner components ties. (see below), Tlfis has the advantage that</td><td colspan=\"3\">SUB index, since items represent prefix infor-mation on a constituent, whereas a PAR index always effects Lind --Rind. Partial string in-formation from higher nodes, which is justified only within the appropriate derivation, nmst</td></tr><tr><td/><td colspan=\"2\">no cyclic items i.e. items with an empty</td><td colspan=\"3\">be distinguished from SUB or PAR indexing</td></tr><tr><td/><td colspan=\"2\">string of parsed symbols, have to be as-</td><td colspan=\"3\">of art item's LHS symbol, which rtlways licences</td></tr><tr><td/><td colspan=\"2\">serted to the chart.</td><td colspan=\"3\">arbitrary substrings. To allow reconstructiort of</td></tr><tr><td colspan=\"3\">* initialization is the special predictor case D(0, S) where 6' is a start symbol.</td><td colspan=\"3\">a derivation, RefList records the pairs of items (or pairs of rule and item, see below) an item is completed from, or it equals lex for lexical</td></tr><tr><td colspan=\"3\">Let V = Cat U Le:e, A --* ,~fl E P and 0 < i < j '< n. Chart[i,j] be the set of arcs</td><td colspan=\"3\">items 'r. To state the chart membership con-dillon of the RPSG variant, we g,~,eralize the hnction gen to nat argnment pair of strings of</td></tr><tr><td colspan=\"3\">between vertices i and j and ~ be the transi-</td><td colspan=\"3\">terminals and possibly indexed rton-termirtals:</td></tr><tr><td colspan=\"3\">tive cover of the derivation relation. Then ev-</td><td/><td/></tr><tr><td colspan=\"3\">ery item in the chart may be characterized by the following membership condition 6 which de-respects both top-down (TD) and bottom-up fective and may indeed contain arbitrary noise (BU) information. Remark that for the (ba-</td><td colspan=\"3\">gen* ' W 4 ~ where gen*(cq/~) = ] iff~3 can be generated from c~ {0, l}</td></tr><tr><td colspan=\"3\">~This mnt~riM wmy Jllow phonologlcM regulariliea, peutlc discourle frott~ tire ULMER TEXTBANI( formation, the acceptance of inpnt strings is s All coxplls evidence reported here ia psychothera-nrembership depends on top-down predictor in-of courlc sis variant of the) Earley algorithm, while item</td><td/><td>lad )</td></tr><tr><td colspan=\"3\">t Therefor% IJanger'l (19Ofl) rettart hemrktlcs teems independent of the predictor (Kilbury 1985).</td><td/><td/></tr><tr><td colspan=\"3\">empirically iltadequate inaafnr at it pomttdate$ a lyn-tactic restart marker. A--~.B c C, hortli, j] iff</td><td/><td>PAn(C).</td><td>for a more formal discussion of</td></tr><tr><td colspan=\"3\">~Jec DSrre 198'T</td><td/><td/></tr></table>", | |
| "num": null, | |
| "type_str": "table", | |
| "text": "RPSGs) are cfgs with a set of start symbols and with rules whose left hand side may be indexed with the keyword SET, SUB, or PAR. The SET index on a rule'! tits licenses the adjlmetion of any start symbol to the right or left of its RHS string. The SUB index licenses arbitrary terminal strings to the right or left of the indexed symbol's lexied projection. The PAR index includes SUB and additionMly licenses any terminal strings within this lexlcal projection. (Left and right sided indices SETL, SUBL and SETII, SUBR,respeetively, are also in use). In a derivation relation --~, for RPSGs an indexed symbol A, r unifies with category A to give A w Formally, SET adjnnetion participates in the cf derivation relation, while SUB and PAIl are interpreted by a recursive generation function gen operating on derivations:where to is a derivation, t its tree structure, Cat;~d the set of indexed or non-indexed nonternfnals and Lea: the set of terminals.The example deri*ation tree(4) shows ,SET adjune-e licensed by an indexed node. Generally, local arbitrariness within a string may be rally modened with an RPSG. Though finite cfls are turned into infinite ones through RPSG indexing, the syntactic description with RPSG is still configurational up to certain local adjnrtctiorts.", | |
| "html": null | |
| } | |
| } | |
| } | |
| } |