Symplectic Geometry
《Symplectic Geometry》 · 第 25 页 · Section 1.11，Definition 1.11.1 及其后 wild 的定义
A point \(p\) in a knot \(K\) is locally flat if there is some neighbourhood \(U\ni p\) such that the pair \((U,U\cap K)\) is homeomorphic to the unit ball, \(B_0(1)\), plus a diameter. A knot \(K\) is locally flat if each point \(p\in K\) is locally flat. […] A point that is not locally flat is called wild, and a knot is wild if any of its points are wild.