Results 11 to 20 of about 14,474 (287)
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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Mathematics, 2022 The limitations of traditional parsing architecture are well known. Even when paired with parsing methods that accept all context-free grammars (CFGs), the resulting combination for any given CFG accepts only a limited subset of corresponding character ...
Žiga Leber +3 more
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A Context-Free Grammar Associated with Fibonacci and Lucas Sequences
Journal of Mathematics, 2023 We introduce a context-free grammar G=s⟶s+d,d⟶s to generate Fibonacci and Lucas sequences. By applying the grammar G, we give a grammatical proof of the Binet formula.
Harold Ruilong Yang
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Grammar Compression with Probabilistic Context-Free Grammar [PDF]
2020 Data Compression Conference (DCC), 2020 We propose a new approach for universal lossless text compression, based on grammar compression. In the literature, a target string $T$ has been compressed as a context-free grammar $G$ in Chomsky normal form satisfying $L(G) = \{T\}$. Such a grammar is often called a \emph{straight-line program} (SLP).
Hiroaki Naganuma +4 more
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Binary Context-Free Grammars [PDF]
Symmetry, 2020 A binary grammar is a relational grammar with two nonterminal alphabets, two terminal alphabets, a set of pairs of productions and the pair of the initial nonterminals that generates the binary relation, i.e., the set of pairs of strings over the terminal alphabets.
Sherzod Turaev +4 more
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On Restricted Context-Free Grammars
Journal of Computer and System Sciences, 2010 AbstractContext-free grammars are widely used for the simple form of their rules. A derivation step consists of the choice of a nonterminal of the sentential form and of an application of a rule rewriting it. Several regulations of the derivation process have been studied to increase the power of context-free grammars.
Dassow, J., Masopust, T. (Tomáš)
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Algorithms, 2016 LR parsing is a popular parsing strategy for variants of Context-Free Grammar (CFG). It has also been used for mildly context-sensitive formalisms, such as Tree-Adjoining Grammar.
Laura Kallmeyer, Wolfgang Maier
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Context-Free Tree Grammars are as Powerful as Context-Free Jungle Grammars
Acta Cybernetica, 2015 Jungles generalize trees by sharing subtrees and allowing garbage. It is shown that IO context-free tree grammars generate the same jungle languages as context-free jungle grammars.
Drewes, F., Engelfriet, J.
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Spurious Ambiguity and Focalization [PDF]
Computational Linguistics, 2018 Spurious ambiguity is the phenomenon whereby distinct derivations in grammar may assign the same structural reading, resulting in redundancy in the parse search space and inefficiency in parsing.
Glyn Morrill, Oriol Valentín
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Journal of Computer and System Sciences, 1974 In an attempt to provide a unified theory of grammars, a model is introduced which has two components. The first is a ''grammar form,'' which provides the general structure of the productions in the grammars to be defined. The second is an ''interpretation'', which yields a specific grammar.
Seymour Ginsburg, Armin B. Cremers
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