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Chomsky Hierarchy

  1. Gheorghe Paun

Published Online: 16 MAR 2009

DOI: 10.1002/9780470050118.ecse581

Wiley Encyclopedia of Computer Science and Engineering

Wiley Encyclopedia of Computer Science and Engineering

How to Cite

Paun, G. 2009. Chomsky Hierarchy. Wiley Encyclopedia of Computer Science and Engineering. 396–403.

Author Information

  1. Institute of Mathematics of the Romanian Academy, Bucharest, Romania

Publication History

  1. Published Online: 16 MAR 2009

Abstract

We introduce Chomsky hierarchy in a formal manner, considering first the basic classes (regular, linear, context-free, context-sensitive, and general grammars), then also introducing a sample intermediate level placed in between context-free and context-sensitive levels, the one defined by the matrix grammars and their “relatives,” the programmed and the random context grammars. A series of properties of the corresponding families of languages are also presented: characterizations and necessary conditions, closure and decidability properties, automata characterizations, and so forth.

Keywords:

  • Chomsky grammar;
  • Chomsky hierarchy;
  • regular language;
  • context-free language;
  • context-sensitive language;
  • computability;
  • Turing machine;
  • finite automaton