Finite regular languages
This chapter describes some functions to deal with finite regular languages.

Dealing with finite regular languages
L is an automaton or a rational expression. This function tests whether its argument represents a finite language or not. gap> RandomRatExp(2); b*(aU@) gap> IsFiniteRegularLanguage(last); false gap> RandomRatExp(2); aUbU@ gap> IsFiniteRegularLanguage(last); true
L is an automaton or a rational expression. This function outputs the recognized language as a list of words. gap> r:=RationalExpression("aaUb(aUb)"); aaUb(aUb) gap> FiniteRegularLanguageToListOfWords(r); [ "aa", "ba", "bb" ]
Given an alphabet alph (a list) and a list of words L (a list of lists), outputs an automaton that recognizes the given list of words. gap> ListOfWordsToAutomaton("ab",["aaa","bba",""]); < deterministic automaton on 2 letters with 6 states > gap> FAtoRatExp(last); (bbUaa)aU@