“…This construction also motivated the study of boundary quotients, an analogue of the Cuntz algebras in the realm of semigroup C * -algebras. On the other hand, in the realm of non-self-adjoint operator algebras, semigroup dynamical systems play a central role in the construction of various semicrossed product algebras and the computation of their C * -envelope [16,13,12,23]. Dilation theory is often a useful tool in these studies.…”