On Rough Fuzzy Prime Ideals in Left Almost Semigroups

In this paper we shall introduce the notion of rough prime ideals and rough fuzzy prime ideals in LA-semigroups. We proved that the lower and the upper approximation of a prime ideal is a prime ideal and we also proved that a fuzzy subset f of an LA-semigroup S is a fuzzy prime ideal of S iff f λ ≠∅ (f λ s ≠∅) is a prime ideal of S for every λ∈[0, 1].