Semi-s-cobordism
In mathematics, a cobordism (W, M, M−) of an (n + 1)-dimensional manifold (with boundary) W between its boundary components, two n-manifolds M and M−, is called a semi-s-cobordism if (and only if) the inclusion M ↪ W {\displaystyle M\hookrightarrow W} is a simple homotopy equivalence (as in an s-cobordism), with no further requirement on the inclusion M − ↪ W {\displaystyle M^{-}\hookrightarrow W} (not even being a homotopy equivalence). == Other notations == The original creator of this topic, Jean-Claude Hausmann, used the notation M− for the right-hand boundary of the cobordism.