帯の融合積

ln this paper, we shall study the question of whieh classes of bands have the strong or the special amalgamation properties. Let A be the variety of bands defined by an identity P = Q. Then A has the strong amalgamation property if and only if P = Q is a permutation identity or heterotypical identity. Moreover, we shall show that the varieties of [left, right] regular bands and left [right] quasinormal bands have the special amalgamation property.