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Formal language

About: Formal language is a research topic. Over the lifetime, 5763 publications have been published within this topic receiving 154114 citations.


Papers
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Journal ArticleDOI
TL;DR: An algorithm for general context-free recognition is given that requires less than n3 time asymptotically for input strings of length n.

349 citations

Book ChapterDOI
21 Jan 1997
TL;DR: This is a survey on combinatorics of words to appear as a chapter in Handbook of Formal Languages about defect effect, equations as properties of words, periodicity, finiteness conditions, avoidabilty and subword complexity.
Abstract: This is a survey on combinatorics of words to appear as a chapter in Handbook of Formal Languages. The topics covered in details are: defect effect, equations as properties of words, periodicity, finiteness conditions, avoidabilty and subword complexity.

347 citations

Book ChapterDOI
TL;DR: To provide complete mathematical flexibility, I shall speak of theories axiomatized within general set theory by defining an appropriate set-theoretical predicate (e.g., ‘is a group’) rather than of theoriesAxiomatization directly within first-order logic as a formal language.
Abstract: To nearly all the members of this Congress, the logical notion of a model of a theory is too familiar to need detailed review here. Roughly speaking, a model of a theory may be defined as a possible realization in which all valid sentences of the theory are satisfied, and a possible realization of the theory is an entity of the appropriate set-theoretical structure. For instance, we may characterize a possible realization of the mathematical theory of groups as an ordered couple whose first member is a nonempty set and whose second member is a binary operation on this set. A possible realization of the theory of groups is a model of the theory if the axioms of the theory are satisfied in the realization, for in this case (as well as in many others), the valid sentences of the theory are defined as those sentences which are logical consequences of the axioms. To provide complete mathematical flexibility I shall speak of theories axiomatized within general set theory by defining an appropriate set-theoretical predicate (e.g., ‘is a group’) rather than of theories axiomatized directly within first-order logic as a formal language. For the purposes of this paper, this difference is not critical. In the set-theoretical case, it is convenient sometimes to speak of the appropriate predicate’s being satisfied by a possible realization. But whichever sense of formalization is used, essentially the same logical notion of model applies.1

328 citations

Book
01 Aug 1996
TL;DR: In this paper, the notions of union, intersection, concatenation, Kleene closure and grammar for fuzzy languages are defined as extensions of the corresponding notions in the theory of formal languages.
Abstract: : A fuzzy language is defined to be a fuzzy subset of the set of strings over a finite alphabet. The notions of union, intersection, concatenation, Kleene closure and grammar for such languages are defined as extensions of the corresponding notions in the theory of formal languages. An explicit expression for the membership function of the language L(G) generated by a fuzzy grammar G is given and it is shown that any context-sensitive fuzzy grammar is recursive. For fuzzy context-free grammars, procedures for constructing the Chomsky and Greibach normal forms are outlined and illustrated by examples. (Author)

324 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237
202237
2021113
2020175
2019173
2018142