抄録
In BCK-algebras, it is well known that a commutative BCKalgebra is as a lower semilattice with respect to the operation ∧. In this paper,
we show that a new class in BCK-algebras which is a proper large class than
the class of the commutative BCK-algebras exists, and this class is as a lower
semilattice with respect to the new operation ×.