TOPOLOGY SHELL
Definition
An object is a <TOPOLOGY SHELL> if and only if: it is an <ARCWISE CONNECTED SPACE>; there exists a <MANIFOLD VOLUME> such that: each point within the shell lies on the boundary; for any point within the <MANIFOLD VOLUME>, there exists an <ORIENTED MANIFOLD SHELL> that is within the <MANIFOLD VOLUME> and that lies between the point within the <MANIFOLD VOLUME> and the boundary