- context-free tree grammar
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English-Chinese computer dictionary (英汉计算机词汇大词典). 2013.
context-free tree grammar
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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 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
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
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
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
Tree-adjoining grammar — (TAG) is a grammar formalism defined by Aravind Joshi. Tree adjoining grammars are somewhat similar to context free grammars, but the elementary unit of rewriting is the tree rather than the symbol. Whereas context free grammars have rules for… … 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
Context-sensitive language — In theoretical computer science, a context sensitive language is a formal language that can be defined by a context sensitive grammar. That is one of the four types of grammars in the Chomsky hierarchy. Of the four, this is the least often used,… … Wikipedia
Formal grammar — In formal semantics, computer science and linguistics, a formal grammar (also called formation rules) is a precise description of a formal language ndash; that is, of a set of strings over some alphabet. In other words, a grammar describes which… … Wikipedia
Mildly context-sensitive language — In formal grammar theory, mildly context sensitive languages are a class of formal languages which can be efficiently parsed, but still possess enough context sensitivity to allow the parsing of natural languages. The concept was first introduced … Wikipedia
Controlled grammar — Controlled grammars[1] are a class of grammars that extend, usually, the context free grammars with additional controls on the derivations of a sentence in the language. A number of different kinds of controlled grammars exist, the four main… … Wikipedia
