2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68756Dror Bar-Natan and Ofer Ron have questioned the accuracy of the statement on page 453, line 2 minus of my paper "Groups of Ribbon Knots", Topology Vol 37, No. 2, 441-458, that "It follows from the inductive proof that $\cal{R}_n$ is of index 2." See their article posted on arXiv: math.GT/0309282. We give here full details of how to carry out the inductive step.2 pages, addendum to q-alg/9502017Geometric Topology57M27text