Reduced languages as omega-generators

International audienceWe consider the following decision problem: “Is a rational omega-language generated by a code ?” Since 1994, the codes admit a characterization in terms of infinite words. We derive from this result the definition of a new class of languages, the reduced languages. A code is a reduced language but the converse does not hold. The idea is to “reduce" easy-to-obtain minimal omega-generators in order to obtain codes as omega-generators