Approximations of

Abstract

This paper concerns the relationship between rough sets, ∈ , ∈ ∨ q k -fuzzy sets, and the LA-semihypergroups. We proved that the lower approximation ( l -approx) and the upper approximation ( u -approx) of different hyperideals of LA-semihypergroups become again hyperideal and also provided some examples. We also provided a result which shows that, if ϑ is not a hyperideal of an LA-semihypergroup P , then its lower approximation is also not a hyperideal.