1, 2, 3 and 4. Then we prove some theorems which characterize the above notions
according to the level subsets. Also we obtain the relationships among these notions, fuzzy
(strong, weak, reflexive) hyper BCK-ideals and fuzzy positive implicative hyper BCK-ideals
of types 5, 6, 7 and 8. Then, we define the notions of fuzzy (weak) implicative hyper BCK-
ideals and we obtain some related results. Finally, by considering the product of two hyper …