Symplectic Geometry
《Symplectic Geometry》 · 第 95–96 页 · Section 4.9，Tangle decomposition（本书允许闭曲线分量）
Let \(S\) be a 2-sphere which meets a link \(L\) transversely in \(2n\) points. […] Because we want \(S\) to bound a ball on both sides, we shall think of \(L\) as embedded in \(S^3\) and let \(U\) be a component of \(S^3-S\). The pair \((U,U\cap L)\) is called an \(n\)-tangle: it is a ball containing \(n\) disjoint properly embedded arcs and a (possibly empty) set of loops.