Volume 35 • Number 4 • 2012   • $\Gamma$-Semihyperrings: Approximations and Rough Ideals S. O. Dehkordi and B. Davvaz Abstract. The notion of rough sets was introduced by Z. Pawlak in 1982. The concept of $\Gamma$-semihyperring is a generalization of semihyperring, $\Gamma$-semiring and semiring. In this paper, we study the notion of a rough (rough prime) ideal in a $\Gamma$-semihyperring. Also, we discuss the relation between the upper and lower rough ideals and the upper and lower approximation of their homomorphism images. 2010 Mathematics Subject Classification: 20N20, 16Y99. Full text: PDF