Rough S-acts
Muhammad Shabir, Muhammad Irfan, Ali Aamir Khan · Lobachevskii Journal of Mathematics · 2008
In this paper we define the notions of rough sub-acts and give some properties of such sub-acts and rough fuzzy sub-acts. We discuss approximations of a subset in acts with respect to Green’s relations. Relationship between upper [lower] rough sub-acts [bi-acts] and upper [lower] aproximations of their homomorphic images are discussed. We also discuss approximations with respect to fuzzy congruences.