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 .