2006/02/06 by Yefim Katsov, Katsov, Yefim
Computer Science · Mathematics · #semigroups and automata theory #Geometric and Algebraic Topology #Logic, Reasoning, and Knowledge
paper · pdf · doi:10.48550/arxiv.math/0602103
In this paper, we prove that all automorphisms of categories of free S-acts are semi-inner, which solves a variation of a well known B. Plotkin's problem in the case of monoids. We also give a description of automorphisms of categories of finitely generated free algebras of varieties of unary algebras, and show that among varieties of unary algebras only the variety of mono-unary algebras is perfect.