Semilattices with closure. (English) Zbl 1088.06003

From the text: We examine the varieties of semilattices (called CSL’s) with an additional closure operator treated as a unary operation. Topics investigated include the word problem in free CSL’s, the lattice of CSL varieties, the finite basis problem for the identities of finite CSL’s and a representation as intersection of closed subsets of topological spaces.


06A12 Semilattices
06A15 Galois correspondences, closure operators (in relation to ordered sets)
08A50 Word problems (aspects of algebraic structures)
08B15 Lattices of varieties
08B20 Free algebras
Full Text: DOI