A comment on “Construction of fuzzy automata from fuzzy regular expressions”

The aim of this comment is to point out that the fuzzy language recognized by a nondeterministic finite automaton, which is associated with a fuzzy regular expression, in the context of Stamenković–Ćirić's method (Stamenković and Ćirić (2012) [11]), is recognized by a fuzzy finite automaton with ε-moves. Every fuzzy automaton with ε-moves is also equivalent to a fuzzy automaton and there are effective methods for removing ε-moves in order to obtain the equivalent fuzzy automaton. In this way, our proposal to convert a fuzzy regular expression to a fuzzy finite automaton is based on the construction of a fuzzy automaton with ε-moves for the fuzzy regular expression and the construction of an equivalent fuzzy finite automaton by means of ε-removal operation.