Each regular code is included in a maximal regular code. (English) Zbl 0609.68053

It is proved here that each regular code is included in a maximal regular code. Other concepts of codes related to maximality are involved. The main result solves a long standing open problem in the theory of formal languages and combinatorial semigroup theory.
Reviewer: T.Harju


68Q45 Formal languages and automata
20M35 Semigroups in automata theory, linguistics, etc.
20M05 Free semigroups, generators and relations, word problems
Full Text: DOI EuDML


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