deterministic context-free grammars
A Generic Parser for Strings and Trees
... by deterministic and nondeterministic context-free grammars Further more, parsing the same string by both parsers has shown that the PA-parser has less number of moves (shifts) by 20% than the ...
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Splittability of bilexical context free grammars is undecidable
... Now let α = uvwxy be a factorization satisfying Ogden’s lemma. If v or x contain one or more occurrences of the symbol $, we can pump such a string in α and obtain a new string which is not a valid computation, which is ...
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Recurrent Neural Networks as Weighted Language Recognizers
... For deterministic probabilistic finite-state au- tomata or context-free grammars only one path or derivation exists for any given string, so the identi- fication of the highest-weighted string ...
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LR(k) Parsing of Coupled Context Free Grammars
... LR(k) Parsing of Coupled Context Free Grammars LIl~(k) I ' m s i n g of C( ut 1 A Cont(xt, ]~ ( c G r a m m a r s ) ) 0 " ~ ~ ~ ' ~ * ~ * G~se]a Pit;sch l ? B l n f o r n l a t i k , U n i v e r s i l[.] ...
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Compound Probabilistic Context Free Grammars for Grammar Induction
... first-order context-free assumptions are generally made not because they represent an ad- equate model of natural language, but because they allow for tractable ...
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Speeding up parsing of biological context free grammars
... Where copyright permits, full text material held in the repository is made freely available online and can be read, downloaded and copied for noncommercial private study or research pur[r] ...
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Practical Parsing of Parallel Multiple Context Free Grammars
... the grammars contain empty ...the grammars. Table 2 contains some statistics about the grammars and table 3 about their non-empty ...FraCaS grammars in- crease by 50 times, while the Resource ...
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Cross Entropy and Estimation of Probabilistic Context Free Grammars
... Probabilistic context-free grammars are able to de- scribe hierarchical, tree-shaped structures underly- ing sentences, and are widely used in statistical nat- ural language processing; see for ...
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Evaluating the Ability of LSTMs to Learn Context Free Grammars
... We conclude that LSTMs do not learn the rele- vant underlying context-free rules, suggesting the good overall performance is attained rather by an efficient way of evaluating nuisance vari- ables. LSTMs are ...
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Incremental Parsing with Parallel Multiple Context Free Grammars
... The algorithm was evaluated with four languages from the GF resource grammar library (Ranta, 2008): Bul- garian, English, German and Swedish. These gram- mars are not primarily intended for parsing but as a resource from ...
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Weighted and Probabilistic Context Free Grammars Are Equally Expressive
... Hidden Markov models (HMMs) are a special case of PCFGs. The structures they produce are labeled sequences, which are equivalent to right-branching trees. We can write an HMM as a PCFG with restricted types of rules. We ...
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Prefix Probability for Probabilistic Synchronous Context Free Grammars
... Our solution to the problem of computing prefix probabilities is formulated in quite different terms from the solutions by Jelinek and Lafferty (1991) and by Stolcke (1995) for probabilistic context-free ...
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Context free commutative grammars with integer counters and resets
... communication- free Petri nets is that their sets of reachable markings are semi-linear [16, 17, 18], meaning in particular that they are closed under all Boolean opera- tions (this is not the case for general ...
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Fast Statistical Parsing with Parallel Multiple Context Free Grammars
... Rparse extracts grammars in two steps. First it converts the treebank into a PMCFG, and then it binarizes that grammar. The binarization pro- cess uses markovization to improve the precision and recall of the ...
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Finite State Approximation of Phrase Structure Grammars
... The approximation is exact for certain contextfree grammars generating regular languages, including all left-linear and right-linear context-free grammars.. The algorithm has been used t[r] ...
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Parsing with Semidirectional Lambek Grammar is NP Complete
... Whereas Lambek grammars generate exactly the context-free languages modulo the missing empty word Pentus 93, the latter generate all permutation closures of context-free languages Benthe[r] ...
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Synchronous Context Free Grammars and Optimal Parsing Strategies
... Synchronous context-free grammars (SCFGs) generalize context-free grammars (CFGs) to generate two strings simultaneously. The formalism dates from the early days of automata ...
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Left To Right Parsing and Bilexical Context Free Grammars
... Abstract We compare the asymptotic time complexity of left-to-right and bidirectional parsing techniques for bilexical context-free grammars, a grammar formalism that is an abstraction o[r] ...
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Removing Left Recursion from Context Free Grammars
... The idea of the algorithm is to eliminate left recursion by transforming the grammar so that all the direct left corners of each nonterminal strictly follow that nonterminal in a fixed t[r] ...
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Pattern Based Context Free Grammars for Machine Translation
... • Synchronization Shieber and Schabes, 1990 of the source and target language structures Readers should note, however, that the pars1See LTAG Schabes, AbeiU~, and Joshi, 1988 Lexicalized[r] ...
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