pumping+lemma+for+context-free+languages

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• Pumping lemma for context-free languages — The pumping lemma for context free languages, also known as the Bar Hillel lemma, is a lemma that gives a property that all context free languages have. Its primary use is to prove a language is not context free.The pumping lemma for context free …   Wikipedia

• Pumping lemma for regular languages — In the theory of formal languages, the pumping lemma for regular languages describes an essential property of all regular languages. Informally, it says that all sufficiently long words in a regular language may be pumped that is, have a middle… …   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

• Pumping lemma — In the theory of formal languages in computability theory, a pumping lemma states that any infinite language of a given class can be pumped and still belong to that class. A language can be pumped if any sufficiently long string in the language… …   Wikipedia

• 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

• Ogden's lemma — In the theory of formal languages, Ogden s lemma (named after William F. Ogden) provides an extension of flexibility over the pumping lemma for context free languages. Ogden s lemma states that if a language L is context free, then there exists… …   Wikipedia

• Computability — You might be looking for Computable function, Computability theory, Computation, or Theory of computation. Computability is the ability to solve a problem in an effective manner. It is a key topic of the field of computability theory within… …   Wikipedia

• Computability theory (computer science) — In computer science, computability theory is the branch of the theory of computation that studies which problems are computationally solvable using different models of computation.Computability theory differs from the related discipline of… …   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

• List of mathematics articles (P) — NOTOC P P = NP problem P adic analysis P adic number P adic order P compact group P group P² irreducible P Laplacian P matrix P rep P value P vector P y method Pacific Journal of Mathematics Package merge algorithm Packed storage matrix Packing… …   Wikipedia