Subsemigroups of free products of semigroups
James Renshaw · Proceedings of the Edinburgh Mathematical Society · 1991
Given amalgams of semigroups [U; Ti] and [U;Si] with U⊆Ti⊆Si, it was proved by Howie in [6] that need not be embedded in . We use the homological techniques developed by Renshaw in [7, 9] and study three new conditions each of which imply the embeddability of the above free products.