OICC Press Mathematical Analysis and its Contemporary Applications 4 2 2022 03 21 t-norms over fuzzy ideals (implicative, positive implicative) of BCK-algebras 10.30495/maca.2021.1942817.1034 EN Rasul Rasuli Department of Mathematics, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran, Iran Journal Article 2022 03 21 In this paper, we use the notion of t-norms to introduce fuzzy subalgebras, fuzzy ideals, fuzzy implicative ideals, fuzzy positive implicative ideals in BCK-algebras. Next, we clarify the links between them and investigate their properties. Finally, we consider them under intersection, cartesian product and homomorphisms(image and pre image) and we study related properties.