In an earlier paper (1986) we have shown the existence of an Eilenberg correspondence between varieties of regular (omega)-languages (N-varieties, for short) and varieties of finite monoids (M-varieties) not being a variety of groups. The aim of this paper is to establish the correspondence in the connection with some operations on languages and on M-varieties. For this, some operations on N-varieties concerning with the shuffle product on (omega)-languages are studied, explicit forms of some N-varieties closed under shuffle product are given. In particular, a new product on (omega)-language and a new operation on N-varieties are introduced and considered. (author). 17 refs. (Atomindex citation 27:046061)
展开▼
