Showing papers on "Chomsky hierarchy published in 2003"
07 Jul 2003
TL;DR: A survey on the various models and their properties is given, their relationships to the language classes of the Chomsky hierarchy are described, and some open problems are presented as mentioned in this paper, where the authors present a set of open problems.
Abstract: The restarting automaton, introduced by Jancar et al in 1995, is motivated by the so-called 'analysis by reduction, ' a technique from linguistics. By now there are many different models of restarting automata, and their investigation has proved very fruitful in that they offer an opportunity to study the influence of various kinds of resources on their expressive power. Here a survey on the various models and their properties is given, their relationships to the language classes of the Chomsky hierarchy are described, and some open problems are presented.
55 citations
TL;DR: The study of P systems with string objects processed by rewriting rules, by investigating some questions which are classic in formal language theory: leftmost derivation, conditional use of rules (permitting and forbidding conditions), relationships with language families in Chomsky and Lindenmayer hierarchies.
36 citations
TL;DR: Two types of languages defined by a string through iterative factor duplications, inspired by the process of tandem repeats production in the evolution of DNA are considered, and some conditions for the non-regularity of these languages are given.
Abstract: We consider two types of languages defined by a string through iterative factor duplications, inspired by the process of tandem repeats production in the evolution of DNA. We investigate some decidability matters concerning the unbounded duplication languages and then fix the place of bounded duplication languages in the Chomsky hierarchy by showing that all these languages are context-free. We give some conditions for the non-regularity of these languages. Finally, we discuss some open problems and directions for further research.
36 citations
01 Nov 2003
TL;DR: This paper aims to provide a history of parsing algorithms and procedures used in the development of parseragnostic systems for knowledge representation in the contexts of knowledge representation and retrieval.
Abstract: attributes, 5 acceptation style, 25 accepting grammar mode, 19 Acoi, 8 Acoi image algebra, 120 Admire, 5 ALGOL 60, 45 alternative production rules, 20, 46 ambiguity, 5, 20, 68 ambiguous feature grammar systems, 39 analysis, 57 AND/OR-graph, 20 annotation extraction algorithm, 5 annotation subsystem, 3 annotations, 4 anonymous symbol, 48 artificial language, 18 atom, 32, 48 atom symbols, 32 atom type, 48 attribute grammars, 97 Australian Open, 128 automaton, 66 auxiliary tree, 82 axiom, 15 back propagation neural network, 57 basic feature grammar system, 29 batch learning algorithms, 58 bidirectional grammars, 19 binary association table (BAT), 99 blackboard architecture, 24 blackbox detector, 56 bottom-up parsing algorithm, 69 bounds, 54 breadth-first parsing algorithm, 70 Chomsky hierarchy, 16 classifier, 57, 95 COBRA, 5, 128 compositional semantics, 5 concept, 6, 54 conceptual level, 126 conditional feature grammar system, 38 conditional grammars, 22 constant, 54 context, 88 context dependency, 6, 113 context globalization, 91 context localization, 91 context-free (CF) grammars, 17 context-sensitive (CS) grammars, 16 controlled named disjunction, 40 controller named disjunction, 40 cooperating distributed (CD) grammar sys- tems, 24 crossed agreements, 17 data repository, 135 database management system (DBMS), 4 dataflow languages, 43 deadlock, 36, 61, 91, 96 deadlock prevention, 36 decision rule, 6, 54, 55 decomposed storage model (DSM), 99 delta operation, 19 dependencies, 33 dependency graph, 111 depth-first parsing algorithm, 69 derivation, 18 derivation mode, 25 derived features, 5 detector, 28, 49 detector confidence, 41, 52
31 citations
TL;DR: This work investigates the relationships between the various McNaughton families, obtaining an extensive hierarchy of classes that includes many well-known language and complexity classes as well as some new classes.
27 citations
TL;DR: The aim of this paper is to give prospective PhD students in the area hints at where to start a promising research; and to supplement earlier reference lists on parallel grammars, trying to cover recent papers as well as ``older'' papers which were somehow neglected in other reviews.
Abstract: The aim of this paper is at least 2 fold: to give prospective PhD students in the area hints at where to start a promising research; and to supplement earlier reference lists on parallel grammars, trying to cover recent papers as well as ``older'' papers which were somehow neglected in other reviews. Together with the nowadays classical book on L systems by G. Rozenberg and A. Salomaa and with the articles on L systems in the Handbook of Formal Languages, researchers will be equipped with a hopefully comprehensive list of references and ideas around parallel grammars.
16 citations
17 Jul 2003
TL;DR: In this paper, a new class of P automata corresponding to the basic classes of languages in the Chomsky hierarchy is introduced and applied to the parsing of (natural language) sentences into dependency trees.
Abstract: New classes of P automata are introduced corresponding to the basic classes of languages in the Chomsky hierarchy. Unlike the previously defined P automata, active P automata are computing with the structure of the membrane systems, using operations like membrane creation, division and dissolution. The model is applied to the parsing of (natural language) sentences into dependency trees.
11 citations
TL;DR: The authors explored specific issues concerning linguistic theory and the use of simplicity criteria in the early Transformational Generative Grammar literature, in particular the influence of Nelson Goodman and Willard Van Orman Quine upon the work of Noam Chomsky during the 1950s.
11 citations
TL;DR: It is argued that considering functional shifts from the viewpoints of both dynamics and computation gives us opposite results about the complexity of systems.
Abstract: We introduce a new type of shift dynamics as an extended model of symbolic dynamics, and investigate the characteristics of shift spaces from the viewpoints of both dynamics and computation. This shift dynamics is called a functional shift that is defined by a set of bi-infinite sequences of some functions on a set of symbols. To analyze the complexity of functional shifts, we measure them in terms of topological entropy, and locate their languages in the Chomsky hierarchy. %Through this study, we argue that complexity of dynamics does not correspond to that of computation. Through this study, we argue that considering functional shifts from the viewpoints of both dynamics and computation give us opposite results about the complexity of systems. We also describe a new class of shift spaces whose languages are not recursively enumerable.
11 citations
Journal Article•
8 citations
Journal Article•
TL;DR: A survey on the various models of restarting automata and their properties is given, their relationships to the language classes of the Chomsky hierarchy are described, and some open problems are presented.
Abstract: The restarting automaton, introduced by Jancar et al in 1995, is motivated by the so-called 'analysis by reduction,' a technique from linguistics. By now there are many different models of restarting automata, and their investigation has proved very fruitful in that they offer an opportunity to study the influence of various kinds of resources on their expressive power. Here a survey on the various models and their properties is given, their relationships to the language classes of the Chomsky hierarchy are described, and some open problems are presented.
TL;DR: This paper introduces advanced elementary formal systems (AEFSs), i.e., elementary formal system which allow for the use of a certain kind of negation, which is nonmonotonic, in essence, and which is conceptually close to negation as failure.
27 Sep 2003
TL;DR: In this paper, a context-free string-graph grammar (one hyperedge is replaced at a time) is used to model discontinuous constituents in natural languages, where the result of a derivation must be formed like a string and nonterminal edges do not have to fulfill this property.
Abstract: Discontinuous constituents are a frequent problem in natural language analyses. A constituent is called discontinuous if it is interrupted by other constituents. In German they can appear with separable verb prefixes or relative clauses in the Nachfeld. They can not be captured by a context–free Chomsky grammar. A subset of hypergraph grammars are string-graph grammars where the result of a derivation must be formed like a string i.e. terminal edges are connected to two nodes and are lined up in a row. Nonterminal edges do not have to fulfill this property. In this paper it is shown that a context–free string-graph grammar (one hyperedge is replaced at a time) can be used to model discontinuous constituents in natural languages.
01 Jan 2003
TL;DR: It is proposed that possible human languages, conceived as term-labeled tree languages consisting of syntactic word trees annotated by semantic lambda terms, can be said to be syntactically homogeneous and finitely illustratable.
Abstract: This paper outlines a new approach to specifying formal constraints on grammars and their languages, in pursuit of more far-reaching statements about possible human languages than, e.g., "they are context-free." We propose that possible human languages, conceived as term-labeled tree languages consisting of syntactic word trees annotated by semantic lambda terms, can be said to be syntactically homogeneous and finitely illustratable. These are new properties of term-labeled tree languages which, when used to specify a subset of all languages generated by a large class of multimodal type-logical grammars, yield a new class of languages which cross-cuts the traditional Chomsky hierarchy. A discovery procedure for type-logical lexicons is then outlined, whose range is proven to generate precisely these languages. Our new approach is actually quite old, having roots in ideas of the American Structuralist school.
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01 Jan 2003
TL;DR: A grammar is a finite system that characterizes a language that contains only terminal symbols, and the language consists of exactly the strings that can be so derived.
Abstract: For the mathematician, an alphabet is a set of symbols and a language is a set, finite or infinite, of strings formed from that alphabet. A grammar is a finite system that characterizes a language. Customarily, grammars work by substitution (i.e. by production). Take the alphabet (or, as it is usually called, the terminal alphabet) of the language VT, add a nonterminal alphabet VN, and a special symbol S that belongs to neither VT, nor VN. A production or rule of substitution, R, is an ordered pair of strings, R = T1 → T2. A grammar is a system, G = 〈 VN, VT, P, S 〉, where P denotes the set of allowable productions. To use the grammar, start with S and find a rule (i.e. a production) S → T1 and substitute T1 for S. Find another rule S1 → T2, such that S1 matches part or all of T1, and substitute T2 for the matched part of T1. Continue with any member of P until the result is a string that contains only terminal symbols. This sequential process is called the derivation of the string, and the final string belongs to the language. The language consists of exactly the strings that can be so derived.
06 Jan 2003
TL;DR: This paper presents techniques for the design and implementation of domain specific languages based on higher-order attribute grammars and presents a domain specific language for pretty-printing and shows how such language can be easily embedded in the specification of a powerful spreadsheet-like tool.
Abstract: This paper presents techniques for the design and implementation of domain specific languages. Our techniques are based on higher-order attribute grammars. Formal languages are specified in the classical attribute formalism and domain specific languages are embedded in the specification via higher-order attributes. We present a domain specific language for pretty-printing and we show how such language can be easily embedded in the specification of a powerful spreadsheet-like tool. From such specification an incremental implementation is automatically derived and the first results are presented.
Book Chapter•
01 Jan 2003
TL;DR: According to Noam Chomsky, speakers of a language have a substantial body of propositional knowledge of that language that they draw upon in language production and comprehension as mentioned in this paper, and one of the most powerful philosophical challenges to Chomsky's output is generated by the rule following considerations of PhilosophicalInvestigations.
Abstract: According to Noam Chomsky, speakers of a language
have a substantial body of propositional knowledge of that
language that they draw upon in language production and
comprehension. Since the late 1950s Chomsky"s project
has been to characterise that knowledge and give an
account of its acquisition. Arguably, one of the most
powerful philosophical challenges to Chomsky"s output is
generated by the rule following considerations of Philosophical
Investigations §§ 138-242. My aim in this paper is to
characterise the nature of this challenge, a topic that,
rather surprisingly, has received relatively little attention in
the philosophical literature.
TL;DR: A universal formal model for interaction is found and the anticipated result may be expressed as a hierarchy that extends Chomsky hierarchy from above, and possible application of the hierarchy is also presented.
Abstract: Interaction, as an important computing paradigm, is far beyond incremental technological development. Various models such as interaction machines and process algebras have been developed to help design and analyze interaction systems. However, little is reported on the computability theory of interaction, and the design and analysis still have to be performed in an ad hoc way. Hence, the question is: how to uniformly evaluate the power of interaction? Roughly, I plan to explore this question in three steps. The first is to find out a universal formal model for interaction. The second is to abstract the tasks of interaction. The third is to evaluate the capability of interaction in terms of the results of step 1 and 2. The anticipated result may be expressed as a hierarchy that extends Chomsky hierarchy from above. Possible application of the hierarchy is also presented.