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Context-free grammar — In formal language theory, a context free grammar (CFG) is a formal grammar in which every production rule is of the form V → w where V is a single nonterminal symbol, and w is a string of terminals and/or nonterminals (w can be empty). The… … Wikipedia
Context-free grammar generation algorithms — are algorithms which generate a context free grammar or grammars from given symbol sequence or sequences.Applications for such algorithms include lossless data compression and data mining. A list of algorithms * Sequitur * Lempel Ziv Welch… … Wikipedia
Stochastic context-free grammar — A stochastic context free grammar (SCFG; also probabilistic context free grammar, PCFG) is a context free grammar in which each production is augmented with a probability. The probability of a derivation (parse) is then the product of the… … Wikipedia
Weighted context-free grammar — A weighted context free grammar (WCFG) is a context free grammar where each production has a numeric weight associated with it. The weight of a parse tree in a WCFG is the weight of the rule used to produce the top node, plus the weights of its… … Wikipedia
Context-sensitive grammar — A context sensitive grammar (CSG) is a formal grammar in which the left hand sides and right hand sides of any production rules may be surrounded by a context of terminal and nonterminal symbols. Context sensitive grammars are more general than… … Wikipedia
Deterministic context-free grammar — In formal grammar theory, the deterministic context free grammars (DCFGs) are a proper subset of the context free grammars. The deterministic context free grammars are those a deterministic pushdown automaton can recognize. A DCFG is the finite… … Wikipedia
Context free — may refer to: Concepts context free grammar deterministic context free grammar stochastic context free grammar weighted context free grammar context free language Software Context Free, a computer language for context free grammars … Wikipedia
Context-free language — In formal language theory, a context free language is a language generated by some context free grammar. The set of all context free languages is identical to the set of languages accepted by pushdown automata. Contents 1 Examples 2 Closure… … Wikipedia
context-free — adjective a) (Of a grammar) which generates sentences in stages, in such a way that at any intermediate stage, any piece of the sentence is enough to determine the corresponding piece at the next stage; that is, the stagewise transformation at a… … Wiktionary
Deterministic context-free language — A deterministic context free language is a formal language which is defined by a deterministic context free grammar.[1] The set of deterministic context free languages is called DCFL[2] and is identical to the set of languages accepted by a… … Wikipedia
