Regular Language - Subclasses

Subclasses

Important subclasses of regular languages include

  • Finite languages - those containing only a finite number of words. These are regular languages, as one can create a regular expression that is the union of every word in the language.
  • Star-free languages, those that can be described by a regular expression constructed from the empty symbol, letters, concatenation and all boolean operators including complementation but not the Kleene star: this class includes all finite languages.
  • Cyclic languages, satisfying the conditions and .

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