Finite Cb-sets

The monoid Cb of injective finite substitutions introduced by Pitts. In fact,the notion of a Cb-set is a generalization of a G-set, where G = Perm(D) is the group ofall finite permutations over a countably infinite set D.In this paper, we give a description of finite Cb-sets and show that injective finite Cb-sets are exactly the ones with a unique zero element. Among other things, we characterizeindecomposable, subdirectly irreducible, and simple finite Cb-sets.

کلیدواژه ها:

Cb-sets ، S-set ، nominal sets