Pawlaks approximations in ? ? -semihypergroups
The ? ? -semihypergroup is a generalization of a semigroup, a generalization of a semihypergroup, and a generalization of a ? ? -semigroup. In this paper, we discuss the roughness of ? ? -subsemihypergroups and ? ? -hyperideals (bi-? ? -hyperideals) in? ? -semihypergroups. In addition, we consider rough sets with respect to the idempotent regular relations in a quotient ? ? -semihypergroup. The upper approximations with respect to Greens equivalence relations are derived in the context of ? ? -subsemihypergroups and ? ? -hyperideals.
approximation semihypergroups rough set ? ? -semihypergroup ? ? ? ? ? ? ? -hyperideal ? ? ? ? ?