Knot Group Epimorphisms, II

Daniel S. Silver, Wilbur Whitten

We consider the relations $\ge$ and ${\ge }_p$ on the collection of all knots, where $k\ge k^{\prime }$ (respectively, $k{\ge }_p{k}^{\prime }$) if there exists an epimorphism $\pi k\to \pi k^{\prime }$ of knot groups…