Release Time:2019-03-11  Hits:

Indexed by: Conference Paper

Date of Publication: 2008-10-18

Included Journals: Scopus、CPCI-S、EI

Volume: 1

Page Number: 448-+

Key Words: rough set; category; topos; middle object; weak topos

Abstract: This paper shall study theory of rough sets from the view of the category theory and topos theory. A category RSC of I-rough sets is presented. Topos properties of the category RSC are studied. It is proved that the category RSC satisfies all properties of a topos except one, for it has no subobject classifier It is pointed that although the category RSC is not a topos, RSC has a middle object and consequently RSC is a weak topos. By the use of weak topos RSC, the operations of I-rough sets are naturally described.