knot complement

《Symplectic Geometry》 · 第 35 页 · Section 2.2 末尾（区分 open complement 与 compact exterior）

In the latter case, we distinguish the compact manifold, called the exterior, from the open one, called the complement. So, for example, if \(K\subset S^3\) is a knot, then \(S^3-K\) is the knot complement, and \(S^3\) minus a small open solid tubular neighbourhood of \(K\) is the knot exterior.