scholarly journals From context-free to definite-clause grammars: a type-theoretic approach

1997 ◽  
Vol 30 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Juergen Haas ◽  
Bharat Jayaraman
Keyword(s):  
Theoretic Approach ◽  
Definite Clause Grammars ◽  
Context Free ◽  
Definite Clause

CHR grammars

2005 ◽  
Vol 5 (4-5) ◽  
pp. 467-501 ◽  
Author(s):  
HENNING CHRISTIANSEN
Keyword(s):  
Logic Programming ◽  
Integrity Constraints ◽  
Bottom Up ◽  
Context Sensitive ◽  
Language Analysis ◽  
Definite Clause Grammars ◽  
Grammar Rules ◽  
High Flexibility ◽  
Definite Clause ◽  
Specification And Implementation

A grammar formalism based upon CHR is proposed analogously to the way Definite Clause Grammars are defined and implemented on top of Prolog. These grammars execute as robust bottom-up parsers with an inherent treatment of ambiguity and a high flexibility to model various linguistic phenomena. The formalism extends previous logic programming based grammars with a form of context-sensitive rules and the possibility to include extra-grammatical hypotheses in both head and body of grammar rules. Among the applications are straightforward implementations of Assumption Grammars and abduction under integrity constraints for language analysis. CHR grammars appear as a powerful tool for specification and implementation of language processors and may be proposed as a new standard for bottom-up grammars in logic programming.

Attribute Grammars and Their Applications

2011 ◽  
pp. 268-273
Author(s):  
Krishnaprasad Thirunarayan
Keyword(s):  
Programming Languages ◽  
Formal Specification ◽  
Attribute Grammars ◽  
Compiler Generation ◽  
Semantics Of Programming Languages ◽  
Definite Clause Grammars ◽  
Language Definition ◽  
Definite Clause ◽  
Specification And Implementation

Attribute grammars are a framework for defining semantics of programming languages in a syntax-directed fashion. In this chapter, we define attribute grammars, and then illustrate their use for language definition, compiler generation, definite clause grammars, design and specification of algorithms, and so forth. Our goal is to emphasize its role as a tool for design, formal specification and implementation of practical systems, so our presentation is example rich.

scholarly journals Definite-clause grammars for 2D shape analysis

1995 ◽  
Vol 30 (8) ◽  
pp. 95-103 ◽  
Author(s):  
E. Bribiesca ◽  
D.A. Rosenblueth ◽  
M. Garza-Jinich
Keyword(s):  
Shape Analysis ◽  
Definite Clause Grammars ◽  
Definite Clause

Formal languages defined by the underlying structure of their words

1988 ◽  
Vol 53 (4) ◽  
pp. 1009-1026 ◽  
Author(s):  
J. P. Ressayre
Keyword(s):  
Natural Extension ◽  
Formal Languages ◽  
Finite Union ◽  
Underlying Structure ◽  
Theoretic Approach ◽  
Local Language ◽  
Infinite Words ◽  
Context Sensitive ◽  
Context Free ◽  
Local Languages

Abstracti) We show for each context-free language L that by considering each word of L as a structure in a natural way, one turns L into a finite union of classes which satisfy a finitary analog of the characteristic properties of complete universal first order classes of structures equipped with elementary embeddings. We show this to hold for a much larger class of languages which we call free local languages, ii) We define local languages, a class of languages between free local and context-sensitive languages. Each local language L has a natural extension L∞ to infinite words, and we prove a series of “pumping lemmas”, analogs for each local language L of the “uvxyz theorem” of context free languages: they relate the existence of large words in L or L∞ to the existence of infinite “progressions” of words included in L, and they imply the decidability of various questions about L or L∞. iii) We show that the pumping lemmas of ii) are independent from strong axioms, ranging from Peano arithmetic to ZF + Mahlo cardinals.We hope that these results are useful for a model-theoretic approach to the theory of formal languages.

scholarly journals A New Top-Down Context-Free Parsing for Syntactic Pattern Recognition

2022 ◽  
Vol 16 ◽  
pp. 23-27
Author(s):  
Mehrnoosh Bazrafkan
Keyword(s):  
Pattern Recognition ◽  
Data Structure ◽  
Time Complexity ◽  
Theoretic Approach ◽  
Top Down ◽  
Syntactic Pattern Recognition ◽  
Context Free Grammar ◽  
Linked List ◽  
Syntactic Pattern ◽  
Context Free

The numerous different mathematical methods used to solve pattern recognition snags may be assembled into two universal approaches: the decision-theoretic approach and the syntactic(structural) approach. In this paper, at first syntactic pattern recognition method and formal grammars are described and then has been investigated one of the techniques in syntactic pattern recognition called top – down tabular parser known as Earley’s algorithm Earley's tabular parser is one of the methods of context -free grammar parsing for syntactic pattern recognition. Earley's algorithm uses array data structure for implementing, which is the main problem and for this reason takes a lots of time, searching in array and grammar parsing, and wasting lots of memory. In order to solve these problems and most important, the cubic time complexity, in this article, a new algorithm has been introduced, which reduces wasting the memory to zero, with using linked list data structure. Also, with the changes in the implementation and performance of the algorithm, cubic time complexity has transformed into O (n*R) order. Key words: syntactic pattern recognition, tabular parser, context –free grammar, time complexity, linked list data structure.

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