An application of Rees theorem to dense regular languages

A language is regular if it can be recognized by a finite automaton.A language is dense if every word in A  is a subword of some word in the language.A non-empty word is a primitive word if it is not a power of any other word,otherwise it is an imprimitive word,Shyr H J and Yu S S conjectured that every dense regular language contains an imprimitive word in .The conjecture is proved by using Rees theorem in this paper.