Covering-based rough sets and modal logics. Part II

摘要

The covering-based rough sets in the system C-2 and bounded N-morphisms form a category CFN. This category is dually equivalent to the category KFS4 in which objects are Kripke S-4-frames and arrows are bounded morphisms. Morphisms over covering structures are defined in order to characterize the modal C-2-definability of classes of finite covering frames. (C) 2018 Elsevier Inc. All rights reserved.