  We introduce the notion of distributivity for implicative-orthomodular
lattices, proving an analogue result of the Foulis-Holland theorem. Based on
this result, we characterize the distributive implicative-orthomodular
lattices. Moreover, we define the center of an implicative-orthomodular lattice
as the set of all elements that commute with all other elements, and we prove
that the center is an implicative-Boolean algebra. Additionally, we give new
characterizations of implicative-orthomodular lattices.
