Showing papers on "Tree-adjoining grammar published in 1994"
TL;DR: The result presented in this paper is that all four of the formalisms under consideration generate exactly the same class of string languages.
Abstract: There is currently considerable interest among computational linguists in grammatical formalisms with highly restricted generative power. This paper concerns the relationship between the class of string languages generated by several such formalisms, namely, combinatory categorial grammars, head grammars, linear indexed grammars, and tree adjoining grammars. Each of these formalisms is known to generate a larger class of languages than context-free grammars. The four formalisms under consideration were developed independently and appear superficially to be quite different from one another. The result presented in this paper is that all four of the formalisms under consideration generate exactly the same class of string languages.
246 citations
04 Oct 1994
TL;DR: A formal semantics for constraint multiset grammars is given, the theoretical complexity of parsing with these grammARS is investigated, and an incremental parsing algorithm is given.
Abstract: Constraint multiset grammars provide a general, high-level framework for the definition of visual languages. They are a new formalism based on multiset rewriting. We give a formal semantics for constraint multiset grammars, investigate the theoretical complexity of parsing with these grammars and give an incremental parsing algorithm. >
139 citations
TL;DR: The definition of tree-adjoining derivation must be reformulated in order to manifest the proper linguistic dependencies in derivations, and the particular proposal is both precisely characterizable, through a compilation to linear indexed grammars, and computationally operational, by virtue of an efficient algorithm for recognition and parsing.
Abstract: The precise formulation of derivation for tree-adjoining grammars has important ramifications for a wide variety of uses of the formalism, from syntactic analysis to semantic interpretation and statistical language modeling We argue that the definition of tree-adjoining derivation must be reformulated in order to manifest the proper linguistic dependencies in derivations The particular proposal is both precisely characterizable through a definition of TAG derivations as equivalence classes of ordered derivation trees, and computationally operational, by virtue of a compilation to linear indexed grammars together with an efficient algorithm for recognition and parsing according to the compiled grammar
132 citations
05 Aug 1994
TL;DR: The various components of the XTAG system are discussed and preliminary evaluation results from the parsing of various corpora are given, and the comparison of XTAG against the IBM statistical parser and the Alvey Natural Language Tool parser is given.
Abstract: This paper present the XTAG system, a grammar development tool based on the Tree Adjoining Grammar (TAG) formalism that includes a wide-coverage syntactic grammar for English. The various components of the system are discussed and preliminary evaluation results from the parsing of various corpora are given. Results from the comparison of XTAG against the IBM statistical parser and the Alvey Natural Language Tool parser are also given.
110 citations
29 Mar 1994
TL;DR: The paper describes a technique that constructs models of symbol sequences in the form of small, human-readable, hierarchical grammars that are both semantically plausible and compact.
Abstract: The paper describes a technique that constructs models of symbol sequences in the form of small, human-readable, hierarchical grammars. The grammars are both semantically plausible and compact. The technique can induce structure from a variety of different kinds of sequence, and examples are given of models derived from English text, C source code and a sequence of terminal control codes. It explains the grammatical induction technique, demonstrates its application to three very different sequences, evaluates its compression performance, and concludes by briefly discussing its use as a method for knowledge acquisition. >
98 citations
Book•
01 Jan 1994
TL;DR: This chapter discusses the basic theory of rigid grammars, a theorem of finite elasticity, and the learnability theorem, which describes the structure of grammar according to k-valued and least-valued values.
Abstract: 1. Introduction 2. Learnability theorem 3. A theorem of finite elasticity 4. Classical categorial grammar 5. Basic theory of rigid grammars 6. Learning from structures I: rigid, k-valued, and least-valued grammar 7. Learning from structures II: Subclasses of the optimal grammars 8. Learning from strings 9. Variations 10. Conclusions Appendix.
50 citations
Journal Article•
TL;DR: The computational problem of parsing a sentence in a tree-adjoining language is investigated and it is shown that any algorithm for the solution of the former problem can easily be converted into an algorithm to solve the latter problem.
Abstract: The computational problem of parsing a sentence in a tree-adjoining language is investigated. An interesting relation is studied between this problem and the well-known computational problem of Boolean matrix multiplication: it is shown that any algorithm for the solution of the former problem can easily be converted into an algorithm for the solution of the latter problem. This result bears on at least two important computational issues. First, we realize that a straightforward method that improves the known upper bound for tree-adjoining grammar parsing is hard to find. Second, we understand which features of the tree-adjoining grammar parsing problem are responsible for the claimed difficulty.
42 citations
04 Oct 1994
TL;DR: A class of relation grammars that satisfy the context-freeness property is defined, which is an essential condition to solve the membership problem in polynomial time, and a predictive parsing algorithm is designed for such Grammars.
Abstract: We define a class of relation grammars that satisfy the context-freeness property, which is an essential condition to solve the membership problem in polynomial time. The context-freeness property is used to design a predictive parsing algorithm for such grammars. The algorithm has a polynomial time behaviour when applied to grammars which generate languages having the additional properties of connections and degree-boundedness. One remarkable result is that a polynomial time complexity is obtained without imposing (total or partial) ordering on the symbols of input sentences. >
39 citations
ALFA1
TL;DR: This paper describes a bidirectional head‐corner parser for (unification‐based versions of) lexicalized tree‐adjoining grammars.
Abstract: This paper describes a bidirectional head-corner parser for (unification-based versions of) lexicalized tree-adjoining grammars.
35 citations
01 May 1994
TL;DR: Substitutions on words and languages applications to cryptography, A. Atanasiu grammar systems - a multi-agent framework for natural language generation, and control mechanisms on #-context-free array grammars.
Abstract: Substitutions on words and languages applications to cryptography, A. Atanasiu grammar systems - a multi-agent framework for natural language generation, E. Csuhaj-Varju control mechanisms on #-context-free array grammars, R. Freund on contextual grammars with parallel derivation, L. Ilie coloured Gauss and tangent codes, J. Kari and V. Niemi matrix grammars versus parallel communicating grammar systems, V. Mihalache reducts vs reducing operators, M. Novotny on conditional grammars and conditional Petri nets, F.-L. Tiplea. (Part Contents).
33 citations
11 Apr 1994
TL;DR: Top-down and bottom-up tree transducers are a tool for proving properties of regular tree grammars used to generate graphs, by generating expressions that denote graphs.
Abstract: Regular tree grammars can be used to generate graphs, by generating expressions that denote graphs. Top-down and bottom-up tree transducers are a tool for proving properties of such graph generating tree grammars.
27 Jun 1994
TL;DR: In this paper, the authors define multiset-valued linear index grammar and unordered vector grammar with dominance links, which are weakly equivalent, and an important subset is at most context-sensitive and polynomially parsable.
Abstract: This paper defines multiset-valued linear index grammar and unordered vector grammar with dominance links. The former models certain uses of multiset-valued feature structures in unification-based formalisms, while the latter is motivated by word order variation and by "quasi-trees", a generalization of trees. The two formalisms are weakly equivalent, and an important subset is at most context-sensitive and polynomially parsable.
TL;DR: This paper compares the generative power of colonies with two cooperation strategies and with several types of the selection of the alphabet for the common language.
27 Jun 1994
TL;DR: The authors define a decidable class of TAGs that is strongly equivalent to CFGs and is cubic-time parsable, which serves to lexicalize CFGs in the same manner as the LCFGs of Schabes and Waters but with considerably less restriction on the form of the grammars.
Abstract: We define a decidable class of TAGs that is strongly equivalent to CFGs and is cubic-time parsable. This class serves to lexicalize CFGs in the same manner as the LCFGs of Schabes and Waters but with considerably less restriction on the form of the grammars. The class provides a normal form for TAGs that generate local sets in much the same way that regular grammars provide a normal form for CFGs that generate regular sets.
TL;DR: This paper investigates the classical regulated rewriting mechanisms like programmed grammars, matrix Grammars and ordered grammARS considered as accepting devices, in contrast with the usual generating mode, and obtains that ordered gramMars with context-free rules, admitting γ-productions, are computationally universal in accepting mode.
Abstract: In this paper, we investigate the classical regulated rewriting mechanisms like programmed grammars, matrix grammars and ordered grammars considered as accepting devices, in contrast with the usual generating mode. Where in the type-n grammars of the Chomsky hierarchy the descriptive power both of generating and of accepting grammars coincide, this need not be true any more in regulated devices. We even obtain, e.g., that ordered grammars with context-free rules and γ-free productions accept all context- sensitive γ-free languages, and that ordered grammars with context-free rules, admitting γ-productions, are computationally universal in accepting mode.
TL;DR: The ideas used to develop original shape grammars are then extended to developed original color grammARS to create new and original designs.
Abstract: Shape grammars have been used with much success to study and represent past and contemporary architectural and other designs. Recently, they have begun to be used to create new and original designs...
01 Nov 1994
TL;DR: It is shown how scrambling facts from Korean can be handled by nonlocal multicomponent TAG (MC‐TAG), and it is argued that overt vWt‐movement in German makes this analysis unattractive, and a new version of MC‐TAG is suggested, called V‐TAG, which can handle both Korean and German word order variation.
Abstract: In many head-final languages such as German, Hindi, Japanese, and Korean, but also in some other languages such as Russian, arguments of a verb can occur in any order. Furthermore, arguments can occur outside of their clause (“long-distance scrambling”). Long-distance scrambling presents a challenge both to linguistic theory and to formal frameworks for linguistic description because it is very unconstrained: in a given sentence, there is no bound on the number of elements that can be scrambled nor on the distance over which each element can scramble. We discuss two formal frameworks related to tree-adjoining grammar. First, we show how scrambling facts from Korean can be handled by nonlocal multicomponent TAG (MC-TAG). Then, we argue that overt vWt-movement in German makes this analysis unattractive, and suggest a new version of MC-TAG, called V-TAG, which can handle both Korean and German word order variation. Interestingly, this new version has more attractive computational properties than nonlocal MC-TAG. We conclude that this formalism is an attractive basis for the development of psycholinguistic processing models and practical parsers alike.
Posted Content•
TL;DR: An efficient algorithm for the application of local grammars put in this form to lemmatized texts is described and illustrated.
Abstract: Local grammars can be represented in a very convenient way by automata. This paper describes and illustrates an efficient algorithm for the application of local grammars put in this form to lemmatized texts.
13 Nov 1994
TL;DR: A truly concurrent semantics for graph grammars, based on event structures, is proposed that generalizes to arbitrary consuminggrammars (i.e., such that each production deletes some items) the semantics presented in [4] for the subclass of safe Grammars.
Abstract: We propose a truly concurrent semantics for graph grammars, based on event structures, that generalizes to arbitrary consuming grammars (i.e., such that each production deletes some items) the semantics presented in [4] for the subclass of safe grammars. Also, parallel derivations are explicitly considered, instead of sequential ones only as in [4]. The “domain” and the “event structure” of a grammar are introduced independently, and one main result shows that they are strongly related, since the domain is the domain of finite configurations of the event structure. Another important result provides an abstract characterization of when two (parallel) graph derivations should be considered as equivalent from a true-concurrency perspective.
19 Apr 1994
TL;DR: In this article, the authors present grammatical descriptions of the set of normal inhabitants of a given type under a given basis, both for the standard simple type system (in the partial discharge convention) and for the system in the total discharge convention (or the Prawitz style natural deduction system).
Abstract: We present grammatical (or equational) descriptions of the set of normal inhabitants {M|??M:A,Min?-normal form} of a given typeAunder a given basis?, both for the standard simple type system (in the partial discharge convention) and for the system in the total discharge convention (or the Prawitz-style natural deduction system). It is shown that in the latter system we can describe the set by a (finite) context-free grammar, but for the standard system this is not necessarily the case because we may need an infinite supply of fresh (bound) variables to describe the set. In both cases, however, our grammars reflect the structure of normal inhabitants in such a way that, when non-terminals are ignored, a derivation tree of the grammars yielding a?-termMcan be identified with B?hm tree ofM. We give some applications of the grammatical descriptions. Among others, we give simple algorithms for the emptiness/finiteness problem of the set of normal inhabitants of a given type (both for the standard and nonstandard systems).
TL;DR: This paper extends previous work on the recognition of imperfect strings generated by fuzzy context-free grammars to the recognition that some strings may not be recognizable when only one change is made to the grammar.
01 Jan 1994
TL;DR: It is shown that dynamic grammars have the formal power of Turing machines and an experimental system which implements a non ambiguous \sl dynamic parser is sketched and applications of this system for the resolution of some semantic analysis problems are shown.
Abstract: We define a dynamic grammar as a device which may generate an unbounded set of context-free grammars, each grammar is produced, while parsing a source text, by the recognition of some construct. It is shown that dynamic grammars have the formal power of Turing machines. For a given source text, a dynamic grammar, when non ambiguous, may be seen as a sequence of usual context-free grammars specialized by this source text: an initial grammar is modified, little by little, while the program is parsed and is used to continue the parsing process. An experimental system which implements a non ambiguous \sl dynamic parser is sketched and applications of this system for the resolution of some semantic analysis problems are shown. Some of these examples are non-trivial (overloading resolution, derived types, polymorphism, \ldots) and indicate that this method may partly compete with other well-known techniques used in type-checking.
TL;DR: This paper focuses on two widely-used "formal" or "logical" representations of gram mars in computational linguistics, Definite Clause Grammars and Feature Structure Grammar, and describes the way in which they express the recognition problem and the parsing problem.
Abstract: A grammar is a formal device which both identifies a certain set of utter ances as well-formed, and which also defines a transduction relation be tween these utterances and their linguistic representations. This paper focuses on two widely-used "formal" or "logical" representations of gram mars in computational linguistics, Definite Clause Grammars and Feature Structure Grammars, and describes the way in which they express the recognition problem (the problem of determining if an utterance is in the language generated by a grammar) and the parsing problem (the problem of finding the analyses assigned by a grammar to an utterance). Although both approaches are 'constraint-based', one of them is based on logical consequence relation, and the other is based on satisfiability. The main goal of this paper is to point out the different conceptual basis of these two ways of formalizing grammars, and discuss some of their properties.
01 Jun 1994
TL;DR: This paper describes a technique for the semantic analysis of visual languages specified by relation grammars based on the definition of Attribute Relation Grammars (ARG), which are an extension of attribute context-freegrammars to the case of non-linear grammar.
Abstract: The general syntactical model of Relation Grammars has been introduced to describe any kind of graphical languages. This paper describes a technique for the semantic analysis of visual languages specified by relation grammars. The technique is based on the definition of Attribute Relation Grammars (ARG), which are an extension of attribute context-free grammars to the case of non-linear grammars. We study the static properties of an ARG under which each sentence can be translated with a cost linear in the size of the sentence.
16 Jul 1994
TL;DR: An algorithm to learn languages defined by structurally reversible deterministic context-free grammars from queries and counterexamples in time polynomial in input size and the size of the original grammar is presented.
Abstract: In this paper we present an algorithm to learn languages defined by structurally reversible deterministic context-free grammars from queries and counterexamples. The algorithm works in time polynomial in input size and the size of the original grammar.A context-free grammar is said to be structurally reversible if among all non-terminal strings that might derive a given terminal string, no one is an extension of the other.The concept of learning from queries and counterexamples was introduced by D. Angluin in 1987. She showed that regular languages are polynomial-time learnable from queries and counterexamples. Since that paper there has been considerable interest in extending the result to a larger class of languages.Among structurally reversible grammars there are very simple grammars which have been recently investigated towards learnability, and weighted grammars. As the complexity of algorithm presented here does not depend on the terminal alphabet size, it is applicable to learning left Szilard languages.Weighted grammars are grammars with integer weights assigned to all symbols such that each rule preserves the weight. The vast majority context-free languages used in practice (for example, most programming languages) can be generated by weighted grammars.
Posted Content•
TL;DR: It will be shown that the best grammars for describing Arabic non-linear morphology are moraic in the case of templatic stems, and affixational inThe paper will demonstrate how the broken plural can be derived under two-level theory via the `implicit' derivation of the singular.
Abstract: This paper demonstrates how a (multi-tape) two-level formalism can be used to write two-level grammars for Arabic non-linear morphology using a high level, but computationally tractable, notation. Three illustrative grammars are provided based on CV-, moraic- and affixational analyses. These are complemented by a proposal for handling the hitherto computationally untreated problem of the broken plural. It will be shown that the best grammars for describing Arabic non-linear morphology are moraic in the case of templatic stems, and affixational in the case of a-templatic stems. The paper will demonstrate how the broken plural can be derived under two-level theory via the `implicit' derivation of the singular.