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Generation and Synchronous TreeAdjoining Grammars
, 1990
"... Treeadjoining grammars (TAG) have been proposed as a formalism for generation based on the intuition that the extended domain of syntactic locality that TAGs provide should aid in localizing semantic dependencies as well, in turn serving as an aid to generation from semantic representations. We dem ..."
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Cited by 677 (39 self)
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Treeadjoining grammars (TAG) have been proposed as a formalism for generation based on the intuition that the extended domain of syntactic locality that TAGs provide should aid in localizing semantic dependencies as well, in turn serving as an aid to generation from semantic representations. We demonstrate that this intuition can be made concrete by using the formalism of synchronous treeadjoining grammars. The use of synchronous TAGs for generation provides solutions to several problems with previous approaches to TAG generation. Furthermore, the semantic monotonicity requirement previously advocated for generation gram mars as a computational aid is seen to be an inherent property of synchronous TAGs.
Tree Insertion Grammar: A CubicTime, Parsable Formalism that Lexicalizes ContextFree Grammar without Changing the Trees Produced
 Computational Linguistics
, 1994
"... this paper, we study the problem of lexicalizing contextfree grammars and show that it enables faster processing. In previous attempts to take advantage of lexicalization, a variety of lexicalization procedures have been developed that convert contextfree grammars (CFGs) into equivalent lexicalize ..."
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Cited by 80 (1 self)
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this paper, we study the problem of lexicalizing contextfree grammars and show that it enables faster processing. In previous attempts to take advantage of lexicalization, a variety of lexicalization procedures have been developed that convert contextfree grammars (CFGs) into equivalent lexicalized grammars. However, these procedures typically suffer from one or more of the following problems
Towards a Uniform Formal Framework for Parsing
 Current Issues in Parsing Technology
, 1991
"... Introduction Many of the formalisms used to define the syntax of natural (and programming) languages may be located in a continuum that ranges from propositional Horn logic to full first order Horn logic, possibly with nonHerbrand interpretations. This structural parenthood has been previously rem ..."
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Cited by 48 (3 self)
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Introduction Many of the formalisms used to define the syntax of natural (and programming) languages may be located in a continuum that ranges from propositional Horn logic to full first order Horn logic, possibly with nonHerbrand interpretations. This structural parenthood has been previously remarked: it lead to the development of Prolog [Col78, Coh88] and is analyzed in some detail in [PerW80] for ContextFree languages and Horn Clauses. A notable outcome is the parsing technique known as Earley deduction [PerW83]. These formalisms play (at least) three roles: descriptive: they give a finite and organized description of the syntactic structure of the language, analytic: they can be used to analyze sentences so as to retrieve a syntactic structure (i.e. a representation) from which the meaning can be extracted, generative: they can also be used as the specification of the concrete representation of sentences from a more
Stochastic Lexicalized ContextFree Grammar
, 1993
"... Stochastic lexicalized contextfree grammar (SLCFG) is an attractive compromise between the parsing efficiency of stochastic contextfree grammar (SCFG) and the lexical sensitivity of stochastic lexicalized treeadjoining grammar (SLTAG). SLCFG is a restricted form of SLTAG that can only generate ..."
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Cited by 43 (6 self)
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Stochastic lexicalized contextfree grammar (SLCFG) is an attractive compromise between the parsing efficiency of stochastic contextfree grammar (SCFG) and the lexical sensitivity of stochastic lexicalized treeadjoining grammar (SLTAG). SLCFG is a restricted form of SLTAG that can only generate contextfree languages and can be parsed in cubic time. However, SLCFG retains the lexical sensitivity of SLTAG and is therefore a much better basis for capturing distributional information about words than SCFG.
Generalized LeftCorner Parsing
 In Sixth Conference of the European Chapter of the Association for Computational Linguistics, Proceedings of the Conference
, 1993
"... We show how techniques known from generalized LR parsing can be applied to leftcorner parsing. The esulting parsing algorithm for contextfree grammars has some advantages over generalized LR parsing: the sizes and generation times of the parsers are smaller, the produced output is more compa ..."
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Cited by 25 (8 self)
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We show how techniques known from generalized LR parsing can be applied to leftcorner parsing. The esulting parsing algorithm for contextfree grammars has some advantages over generalized LR parsing: the sizes and generation times of the parsers are smaller, the produced output is more compact, and the basic parsing technique can more easily be adapted to arbitrary contextfree grammars.
Bidirectional Parsing Of Lexicalized Tree Adjoining Grammars
, 1991
"... In this paper a bidirectional parser for Lexicalized Tree Adjoining Grammars will be presented. The algorithm takes advantage of a peculiar characteristic of Lexicalized TAGs, i.e. that each elementary tree is associated with a lexical item, called its anchor. The algorithm employs a mixed strategy: ..."
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Cited by 21 (1 self)
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In this paper a bidirectional parser for Lexicalized Tree Adjoining Grammars will be presented. The algorithm takes advantage of a peculiar characteristic of Lexicalized TAGs, i.e. that each elementary tree is associated with a lexical item, called its anchor. The algorithm employs a mixed strategy: it works bottom up from the lexical anchors and then expands (.partial) analyses making topdown predictions. Even if such an algorithm does not improve the worstcase time bounds of already known TAGs parsing methods, it could be relevant from the perspective of linguistic information processing, because it employs lexical information in a more direct way.
The Computational Complexity of the CorrectPrefix Property for TAGs
 COMPUTATIONAL LINGUISTICS
, 1999
"... ..."
Solving the correctprefix property for TAGs
 Proc. of the Fifth Meeting on Mathematics of Language, pages 124130, Schloss Dagstuhl
, 1997
"... We present a new upper bound for the computational complexity of the parsing problem for TAGs, under the constraint that input is read from left to right in a way that errors in the input are observed as soon as possible, which is called the correctprefix property. The former upper bound was O(n ..."
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Cited by 9 (0 self)
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We present a new upper bound for the computational complexity of the parsing problem for TAGs, under the constraint that input is read from left to right in a way that errors in the input are observed as soon as possible, which is called the correctprefix property. The former upper bound was O(n 9 ), which we now improve to O(n 6 ), which is the same as that of practical parsing algorithms for TAGs without the additional constraint of the correctprefix property. Thereby we show that the correctprefix property does not require significant additional costs. 1 Introduction Traditionally, parsers and recognizers for regular and contextfree languages process input from left to right. If a syntax error occurs in the input they often detect that error immediately after its position is reached. The position of the syntax error can be defined as the last input symbol of the shortest prefix which cannot be extended to be a correct sentence in the language L. In formal notation, this p...
Lexicalized ContextFree Grammar: A CubicTime Parsable, Lexicalized Normal Form for ContextFree Grammar That Preserves Tree Structure
, 1993
"... Lexicalized contextfree grammar (LCFG) is a treebased formalism that makes use of both tree substitution and a restricted form of tree adjunction. Because of its use of adjunction, LCFG allows sufficient freedom in the way derivations can be performed that lexicalization of contextfree grammar ..."
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Cited by 7 (4 self)
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Lexicalized contextfree grammar (LCFG) is a treebased formalism that makes use of both tree substitution and a restricted form of tree adjunction. Because of its use of adjunction, LCFG allows sufficient freedom in the way derivations can be performed that lexicalization of contextfree grammars (CFGs) is possible while preserving the structure of the trees derived by the CFGs. However, the tree adjunction permitted is sufficiently restricted that LCFGs are stringwise equivalent to CFGs and have the same cubictime worstcase complexity bounds for recognition and parsing.
A Left Corner Parser for Tree Adjoining Grammars
, 2002
"... Introduction Tabular parsers can be dened as deduction systems where formulas, called items, are sets of complete or incomplete constituents (Sikkel, 1997; Shieber, Schabes and Pereira, 1995). Formally, given an input string w = a 1 . . . a n with n 0 and a grammar G, a parser IP is a tuple (I, ..."
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Cited by 2 (1 self)
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Introduction Tabular parsers can be dened as deduction systems where formulas, called items, are sets of complete or incomplete constituents (Sikkel, 1997; Shieber, Schabes and Pereira, 1995). Formally, given an input string w = a 1 . . . a n with n 0 and a grammar G, a parser IP is a tuple (I, H,D) is a set of items, H is a set of hypothesis ([a i , i  1, i] with 1 n) that encodes the input string, and is a set of deduction steps that determines how items are combined in order to deduce new items. The deductive approach allows us to establish relations between two parsers in a formal way. One of the most interesting relations between parsers are lters because they can be used to improve the performance of tabular parsers in practical cases. The application of a lter to a parser yields a new parser which performs less deductions or contracts sequences of deductions to single deduction steps. One wellknown example of a lter is the relation between Earley and Left