Showing papers on "Context-sensitive grammar published in 1990"
TL;DR: In this paper, an efficient algorithm for learning context-free grammars using two types of queries, structural equivalence queries and structural membership queries, is presented. But it is not shown that a grammar learned by the algorithm is not only a correct grammar but also structurally equivalent to it.
176 citations
Book Chapter•
01 Jan 1990
TL;DR: This paper has described a formalism, the linear context-free rewriting system (LCFR), as a first attempt to capture the closeness of the derivation structures of these formalisms, and shown that LCFRs are equivalent to muticomponent tree adjoining grammars (MCTAGs), and also briefly discussed some variants of TAG.
Abstract: Investigations of classes of grammars that are nontransformational and at the same time highly constrained are of interest both linguistically and mathematically. Context-free grammars (CFG) obviously form such a class. CFGs are not adequate (both weakly and strongly) to characterize some aspects of language structure. Thus how much more power beyond CFG is necessary to describe these phenomena is an important question. Based on certain properties of tree adjoining grammars (TAG) an approximate characterization of class of grammars, mildly context-sensitive grammars (MCSG), has been proposed earlier. In this paper, we have described the relationship between several different grammar formalisms, all of which belong to MCSG. In particular, we have shown that head grammars (HG), combinatory categorial grammars (CCG), and linear indexed grammars (LIG) and TAG are all weakly equivalent. These formalisms are all distinct from each other at least in the following aspects: (a) the formal objects and operations in each formalism, (b) the domain of locality over which dependencies are specified, (c) the degree to which recursion and the domain of dependencies are factored, and (d) the linguistic insights that are captured in the formal objects and operations in each formalism. A deeper understanding of this convergence is obtained by comparing these formalisms at the level of the derivation structures in each formalism. We have described a formalism, the linear context-free rewriting system (LCFR), as a first attempt to capture the closeness of the derivation structures of these formalisms. LCFRs thus make the notion of MCSGs more precise. We have shown that LCFRs are equivalent to muticomponent tree adjoining grammars (MCTAGs), and also briefly discussed some variants of TAGs, lexicalized TAGs, feature structure based TAGs, and TAGs in which local domination and linear precedence are factored TAG(LD/LP). Disciplines Computer Sciences Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-90-01. This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/539 The Convergence Of Mildly Context-Sensitive Grammar Formalisms MS-CIS-90-01 LINC LAB 161 Aravind K. Joshi K. Vijay Shanker David Weir Department of Computer and Information Science School of Engineering and Applied Science University of Pennsylvania Philadelphia, PA 19104-6389
175 citations
05 Mar 1990
TL;DR: The very high level language PROGRESS as discussed by the authors is the first statically typed language which is based on the concepts of PRO grammed Graph RE-writing SyStems and it supports different programming paradigms by offering procedural and declarative programming constructs.
Abstract: The Very High Level language PROGRESS presented within this paper is the first statically typed language which is based on the concepts of PRO grammed Graph RE-writing SyStems. This language supports different programming paradigms by offering procedural and declarative programming constructs for the definition of integrity constraints, functional attribute dependencies, derived binary relationships, atomic graph rewrite rules, and complex graph transformations.
101 citations
TL;DR: It is shown that the class of boundary graph languages is closed under the operation of edge contraction, where the label of the edge indicates whether or not the edge should be contracted.
Abstract: Context-free hypergraph grammars and boundary graph grammars of bounded nonterminal degree have the same power, both for generating sets of graphs and for generating sets of hypergraphs. Arbitrary boundary graph grammars have more graph generating power than context-free hypergraph grammars, but they have the same hypergraph generating power. To obtain these results, several normal forms for boundary graph grammars are given. It is also shown that the class of boundary graph languages is closed under the operation of edge contraction, where the label of the edge indicates whether or not the edge should be contracted.
72 citations
05 Mar 1990
TL;DR: An elementary introduction to the notion of an NLC graph grammar is given, and several of its extensions and variations are discussed in a systematic way.
Abstract: An elementary introduction to the notion of an NLC graph grammar is given, and several of its extensions and variations are discussed in a systematic way. Simple concepts are considered rather than technical details.
58 citations
TL;DR: This work investigates this type of graph grammar and shows that the use of edge labels (together with the NCE feature) is responsible for some new properties, and proves that the class of (boundary) eNCE languages properly contains the closure of theclass of ( boundary) NLC languages under node relabelings.
49 citations
TL;DR: A formal declarative notation for describing the semantics and translation of programming languages, and the various components of the description cannot be decomposed into modules.
Abstract: Attribute grammars provide a formal declarative notation for describing the semantics and translation of programming languages. Describing any real programming language is a significant software engineering challenge. From a software engineering viewpoint, current notations for attribute grammars have two flaws: tedious repetition of essentially the same attribute computations is inevitable, and the various components of the description cannot be decomposed into modules.… — From the Authors' Abstract
45 citations
05 Mar 1990
TL;DR: S-HH grammars have the same graph generating power as the vertex rewriting context-free NCE graph Grammars, and as recursive systems of equations with four types of simple operations on graphs.
Abstract: Separated handle-rewriting hypergraph grammars (S-HH grammars) are introduced, where separated means that the nonterminal handles are disjoint. S-HH grammars have the same graph generating power as the vertex rewriting context-free NCE graph grammars, and as recursive systems of equations with four types of simple operations on graphs.
42 citations
20 Jun 1990
TL;DR: It is shown that every pushdown automaton can be transformed into a graph grammar generating its transition graph, and that this transformation can be applied to any graph grammar.
Abstract: We saw (in section 1) that we can transform every pushdown automaton into a graph grammar generating its transition graph.
37 citations
TL;DR: The approach makes it possible to reduce the problem of inferring the structure of a context-free grammar back to the normal grammatical inference problem.
26 citations
20 Aug 1990
TL;DR: It will be shown how unification grammars can be used to build a reversible machine translation system and how to obtain a completely reversible MT system using a series of (bidirectional) unification Grammars.
Abstract: In this paper it will be shown how unification grammars can be used to build a reversible machine translation system.Unification grammars are often used to define the relation between strings and meaning representations in a declarative way. Such grammars are sometimes used in a bidirectional way, thus the same grammar is used for both parsing and generation. In this paper I will show how to use bidirectional unification grammars to define reversible relations between language dependent meaning representations. Furthermore it is shown how to obtain a completely reversible MT system using a series of (bidirectional) unification grammars.
TL;DR: It is shown that these grammars with productions having associated only words consisting of one or two symbols characterize type 0 languages.
Abstract: Each production of a generalized forbidding grammar has an associated finite set of words. Such a production can be applied only if none of its associated words is a substring of a given rewritten sentential form. It is shown that these grammars with productions having associated only words consisting of one or two symbols characterize type 0 languages
TL;DR: In this article the formal definitions of modifiable grammars are presented, and the equivalence between classes ofModifiable gramMars and Turing machines is proved, and some criteria for reducing modifiablegrammars to context-free grammARS are provided.
Abstract: In this article the formal definitions of modifiable grammars are presented, and the equivalence between classes of modifiable grammars and Turing machines is proved. Some criteria for reducing modifiable grammars to context-free grammars are provided. A lazy LR(1) algorithm for context-free grammars and an algorithm for constructing a LR(1) parser for modifiable grammars are discussed.
05 Mar 1990
TL;DR: In this paper, the authors investigate the relationship between the algebraic definition of graph grammars and logic programming, and show that the operational semantics of any logic program can be faithfully simulated by a particular context-free hypergraph grammar.
Abstract: In this paper we investigate the relationship between the algebraic definition of graph grammars and logic programming. In particular, we show that the operational semantics of any logic program can be faithfully simulated by a particular context-free hypergraph grammar. In the process of doing that, we consider the issue of representing terms, formulas, and clauses as particular graphs or graph productions, by first evaluating the approaches already proposed for Term Rewriting Systems (TRS), and then by giving an original extension of those approaches, to be able to deal with the unique features of logic programming. Actually, not only does our representation of definite clauses by graph productions allow us to deal correctly with logical unification, but also it overcomes some of the problems encountered by other approaches for representing TRS's as graph grammars. The main result of the paper states the soundness and completeness of the representation of clauses by productions, and this correspondence is extended to entire computations, showing how a context-free grammar (over a suitable category of graphs) can be associated with a logic program. The converse holds as well, i.e. given any context-free graph grammar (over that category), a logic program can be extracted from it.
04 Oct 1990
TL;DR: Relation grammars (RGs) are introduced as a possible general framework for specifying the syntax of visual languages and, more generally, of multi-dimensional languages.
Abstract: Relation grammars (RGs) are introduced as a possible general framework for specifying the syntax of visual languages and, more generally, of multi-dimensional languages. A formal definition of relation grammars is given. Two examples of applications on graphs are shown. RG formalism is compared to conventional context-free grammars. RGs are used to describe the syntax of horizontal lines and statechart graphs using picture processing grammars and picture layout grammars, respectively. >
TL;DR: A general pattern-recognition procedure for application to unconstrained alphanumeric characters is presented, and preliminary experimental results indicate recognition rates comparable to the state of the art, but with a considerable reduction in computing time.
Abstract: A general pattern-recognition procedure for application to unconstrained alphanumeric characters is presented. The procedure is designed to allow hierarchical redescription of the input images in terms of significant elements only, and formal developments are given within the framework of elementary phrase-structure grammars. The extraction of the primitives associated with the terminal vocabularies of the grammars is always deterministic, and the productions of the parsers are characterized by a significant degree of topological fidelity. Preliminary experimental results indicate recognition rates comparable to the state of the art, but with a considerable reduction in computing time. >
TL;DR: The investigated topics are: closure properties, the efficiency of generating a (linear) language by such a system compared with usual grammars, hierarchies, and so on.
Abstract: We continue the study of parallel communicating grammar systems introduced in P[acaron]un and Sântean [7] as a grammatical model of parallel computing. The investigated topics are: closure properties, the efficiency of generating a (linear) language by such a system compared with usual grammars, hierarchies.
24 Jun 1990
TL;DR: Augmented phrase structure grammar (APSG) formalisms can express many of the relevant syntactic and semantic regularities of spoken language systems, but they are computationally less suitable for language modeling, because of the inherent cost of computing state transitions in APSG parsers.
Abstract: Grammars for spoken language systems are subject to the conflicting requirements of language modeling for recognition and of language analysis for sentence interpretation. Current recognition algorithms can most directly use finite-state acceptor (FSA) language models. However, these models are inadequate for language interpretation, since they cannot express the relevant syntactic and semantic regularities. Augmented phrase structure grammar (APSG) formalisms, such as unification grammars, can express many of those regularities, but they are computationally less suitable for language modeling, because of the inherent cost of computing state transitions in APSG parsers.
Book•
01 Jun 1990TL;DR: Implementing relational database languages in Prolog parsing as a logical constraint satisfaction features, frames and quantifier-free formulae a natural language processing system based on government binding theory restriction grammar and the analysis of discourse producing co-operative answers in deductive databases grammars bi-directionally through controlled deduction.
Abstract: Implementing relational database languages in Prolog parsing as a logical constraint satisfaction features, frames and quantifier-free formulae a natural language processing system based on government binding theory restriction grammar - a logic grammar reference resolution in PUNDIT natural language processing in the experimental discourse understanding system DUALS-III logic programming and the analysis of discourse producing co-operative answers in deductive databases grammars bi-directionally through controlled deduction.
01 Jan 1990
TL;DR: In this paper, the problem of attribute evaluation during LR parsing is considered and several definitions of LR-attributed grammars are presented, and relations of corresponding attribute grammar classes are analyzed.
Abstract: The problem of attribute evaluation during LR parsing is considered. Several definitions of LR-attributed grammars are presented. Relations of corresponding attribute grammar classes are analysed. Also the relations between LR-attributed grammars and LL-attributed grammars and between LR-attributed grammars and a class of one-pass attributed grammars based on left-corner grammars are considered.
05 Mar 1990
TL;DR: An overview how notions in the theory of grammars and that of module specifications correspond to each other and discuss how both theories can benefit from each other is given.
Abstract: Algebraic specification grammars have recently been introduced implicitly by the second author as a new kind of graph grammars in order to generate algebraic specifications using productions and derivations. In fact, in the well-known algebraic approach to graph grammars, also known as "Berlin-approach", we mainly have to replace the category of graphs by the category of algebraic specifications to obtain the basic definitions, constructions and results for this new kind of grammars. Since a production in an algebraic specification grammars corresponds exactly to an interface of an algebraic module specification for modular software systems this new kind of grammars can be used for modular system design. For this purpose we give an overview how notions in the theory of grammars and that of module specifications correspond to each other and discuss how both theories can benefit from each other. Concerning full technical detail and proofs we refer to other published or forthcoming papers.
TL;DR: This paper investigates various natural restrictions on RDNLC languages andRDNLC grammars and their influence on the complexity of the membership problem and demonstrates that these restrictions lead to logarithmic space recognition algorithms.
Proceedings Article•
01 May 1990
04 Oct 1990
TL;DR: The replacement of pointers with graph grammar productions is discussed, which provides a substantial improvement in the programming model used, makes better use of current high-resolution screen technology than a strictly text-based language, and provides improved support for parallel processing due to characteristics of the graph grammar formulation used.
Abstract: The replacement of pointers with graph grammar productions is discussed. Such a replacement provides a substantial improvement in the programming model used, makes better use of current high-resolution screen technology than a strictly text-based language, and provides improved support for parallel processing due to characteristics of the graph grammar formulation used. The background of this project, and the relationship to visual languages, is described. The use of graph grammars in programming and the graph grammar programming languages are described. The editing environment being developed for programming in graph grammars is presented. Compiler development for the system is described. >
01 Sep 1990
TL;DR: In this article, the problem of attribute evaluation during LR parsing is considered and several definitions of LR-attributed grammars are presented, and relations of corresponding attribute grammar classes are analyzed.
Abstract: The problem of attribute evaluation during LR parsing is considered. Several definitions of LR-attributed grammars are presented. Relations of corresponding attribute grammar classes are analysed. Also the relations between LR-attributed grammars and LL-attributed grammars and between LR-attributed grammars and a class of one-pass attributed grammars based on left-corner grammars are considered.
20 Aug 1990
TL;DR: A modification of the Cocke-Younger-Kasami parsing algorithm is defined which covers this additional deductive power and analyzes its time complexity.
Abstract: Instead of incorporating a gap-percolation mechanism for handling certain "movement" phenomena, the extended categorial grammars contain special inference rules for treating these problems. The Lambek categorial grammar is one representative of the grammar family under consideration. It allows for a restricted use of hypothetical reasoning. We define a modification of the Cocke-Younger-Kasami (CKY) parsing algorithm which covers this additional deductive power and analyze its time complexity.
01 Sep 1990
TL;DR: Coding with algebraic languages and defining some semantics of these languages with attribute grammars can give a non-algebraic system of equations satisfied by the generating function.
Abstract: In this paper, we are interested in counting some combinatorial objects in ℕ×ℕ that are polyominoes. More precisely, we want some information about their generating function according to the following parameters perimeter and area. Coding with algebraic languages and defining some semantics of these languages with attribute grammars, we can give a non-algebraic system of equations satisfied by the generating function. In some cases, we infer new exact results from this system.
01 Sep 1990
TL;DR: In this article, the role of attribute grammars and functional programming languages in program transformation tools is studied, starting from their own experiences with designing and implementing two such tools, the OPTRAN transformer generator and the functional language TrafoLa, and compare those with other systems, e.g. the Cornell Synthesizer Generator and the Flagship tuples environment.
Abstract: The role of attribute grammars and functional programming languages in program transformation tools is studied. Starting from our own experiences with designing and implementing two such tools, the OPTRAN transformer generator and the functional language TrafoLa, we compare those with other systems, e.g. the Cornell Synthesizer Generator and the Flagship tuples environment. Some design hints are derived from this comparison.