theory, a context-free grammar (CFG) is a formal grammar whose production rules can be applied to a nonterminal symbol regardless of its context. In particular...

Generalized context-free grammar (GCFG) is a grammar formalism that expands on context-free grammars by adding potentially non-context-free composition...

Context-free may refer to: Context-free grammar Deterministic context-free grammar Generalized context-free grammar Probabilistic context-free grammar...

Generalized phrase structure grammar (GPSG) is a framework for describing the syntax and semantics of natural languages. It is a type of constraint-based...

Joshi characterized "grammars (and associated languages) that are only slightly more powerful than context-free grammars (context-free languages)". He called...

important feature of all transformational grammars is that they are more powerful than context-free grammars. Chomsky formalized this idea in the Chomsky...

Straight-line grammars (more precisely: straight-line context-free string grammars) can be generalized to Straight-line context-free tree grammars. The latter...

context-sensitive language is a language that can be defined by a context-sensitive grammar (and equivalently by a noncontracting grammar). Context-sensitive...

restricted grammars in the Chomsky hierarchy: context-sensitive grammars or context-free grammars. In a broader sense, phrase structure grammars are also...

for context-free languages, also known as the Bar-Hillel lemma, is a lemma that gives a property shared by all context-free languages and generalizes the...

can be similarly proved to be not context-free. This led to the abandonment of Generalized Phrase Structure Grammar once cross-serial dependencies were...

The Standard Generalized Markup Language (SGML; ISO 8879:1986) is a standard for defining generalized markup languages for documents. ISO 8879 Annex A...

of Generalized Phrase Structure Grammar; the ID/LP Grammar approach is also used in head-driven phrase structure grammar, lexical functional grammar, and...

Head grammar (HG) is a grammar formalism introduced in Carl Pollard (1984) as an extension of the context-free grammar class of grammars. Head grammar is...

City F.C. The Gold Coast Suns Gold Coast United Football Club Generalized context-free grammar or GCFC Get Coffee From Cafe See also: Guildford (city) and...

L-system's grammar. An L-system is context-free if each production rule refers only to an individual symbol and not to its neighbours. Context-free L-systems...

Backus-Naur form Categorial grammar Chomsky hierarchy Concatenation Context-free grammar Context-sensitive grammar Context-sensitive language Decidable...

Indexed grammars are a generalization of context-free grammars in that nonterminals are equipped with lists of flags, or index symbols. The language produced...

interesting non-context-free languages such as the classic example {anbncn}. A GTDPL grammar can be reduced to an equivalent TDPL grammar that recognizes...

equivalent to conjunctive grammars in the same way as nondeterministic PDA are equivalent to context-free grammars. Context-free grammar Counter automaton Finite-state...

(generalized left-to-right rightmost derivation parser) is an extension of an LR parser algorithm to handle non-deterministic and ambiguous grammars....

A simple precedence grammar is a context-free formal grammar that can be parsed with a simple precedence parser. The concept was first created in 1964...

denoted L(R). A generalized regular expression can be one of the following (where a is a symbol of the alphabet A, and R and S are generalized regular expressions):...

Ogden's lemma—If a language L {\displaystyle L} is generated by a context-free grammar, then there exists some p ≥ 1 {\displaystyle p\geq 1} such that ∀...

Conjunctive grammars are a class of formal grammars studied in formal language theory. They extend the basic type of grammars, the context-free grammars, with...

not context-free, some kind of context-free approximation to the grammar is used to perform a first pass. Algorithms which use context-free grammars often...

structure grammar (PSG) from the lexicon simplifies PS rules to being a context-free rule (B → D) as opposed to being context sensitive (ABC → ADC). Context-sensitive...

longer/any more See also English grammar § Negation, and Affirmation and negation § Multiple negation. The actual set of contexts that license particular polarity...

LR(1) parsers, and generalized LR parsers (GLR parsers). LR parsers can be generated by a parser generator from a formal grammar defining the syntax...

ISBN 0-201-02988-X. Here: p.217 (left, right-regular grammars as subclasses of context-free grammars), p.79 (context-free grammars) Hopcroft and Ullman 1979 (p.229, exercise...