Results 11 to 20 of about 52,651 (265)
Undecidable problems concerning densities of languages [PDF]
Discrete Mathematics & Theoretical Computer Science, 2005 In this paper we prove that the question whether a language presented by a context free grammar has density, is undecidable. Moreover we show that there is no algorithm which, given two unambiguous context free grammars on input, decides whether the ...
Jakub Kozik
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Higher-Order Operator Precedence Languages [PDF]
Electronic Proceedings in Theoretical Computer Science, 2017 Floyd's Operator Precedence (OP) languages are a deterministic context-free family having many desirable properties. They are locally and parallely parsable, and languages having a compatible structure are closed under Boolean operations, concatenation ...
Stefano Crespi Reghizzi, Matteo Pradella
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J. Autom. Lang. Comb., 2023 Context-free languages can be characterized in several ways. This article studies projective linearisations of languages of simple dependency trees, i. e., dependency trees in which a node can govern at most one node with a given syntactic function. We prove that the projective linearisations of local languages of simple dependency trees coincide with ...
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Optimizing over subsequences generates context-sensitive languages
Transactions of the Association for Computational Linguistics, 2021 Phonological generalizations are finite-state. While Optimality Theory is a popular framework for modeling phonology, it is known to generate non-finite-state mappings and languages. This paper demonstrates that Optimality Theory is capable of generating
Andrew Lamont
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Context-Free Languages, Coalgebraically [PDF]
, 2011 We give a coalgebraic account of context-free languages using the functor D(X) = 2 × XA for deterministic automata over an alphabet A, in three different but equivalent ways: (i) by viewing context-free grammars as D-coalgebras; (ii) by defining a format for behavioural differential equations (w.r.t.
J. Winter (Joost) +2 more
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Regular Languages and Associative Language Descriptions [PDF]
Discrete Mathematics & Theoretical Computer Science, 2007 The Associative Language Description model (ALD) is a combination of locally testable and constituent structure ideas. It is consistent with current views on brain organization and can rather conveniently describe typical technical languages such as ...
Marcella Anselmo +2 more
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Bounded-oscillation Pushdown Automata [PDF]
Electronic Proceedings in Theoretical Computer Science, 2016 We present an underapproximation for context-free languages by filtering out runs of the underlying pushdown automaton depending on how the stack height evolves over time. In particular, we assign to each run a number quantifying the oscillating behavior
Pierre Ganty, Damir Valput
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Chomsky-Schützenberger parsing for weighted multiple context-free languages
Journal of Language Modelling, 2017 We prove a Chomsky-Schützenberger representation theorem for multiple context-free languages weighted over complete commutative strong bimonoids. Using this representation we devise a parsing algorithm for a restricted form of those devices.
Tobias Denkinger
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Complexity of Problems of Commutative Grammars [PDF]
Logical Methods in Computer Science, 2015 We consider commutative regular and context-free grammars, or, in other words, Parikh images of regular and context-free languages. By using linear algebra and a branching analog of the classic Euler theorem, we show that, under an assumption that the ...
Eryk Kopczynski
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On Intuitionistic Fuzzy Context-Free Languages
Journal of Applied Mathematics, 2013 Taking intuitionistic fuzzy sets as the structures of truth values, we propose the notions of intuitionistic fuzzy context-free grammars (IFCFGs, for short) and pushdown automata with final states (IFPDAs).
Jianhua Jin, Qingguo Li, Chunquan Li
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