Remark 8.1.6. Assume is terminal for . Consider an isomorphism of curves fixing . Note that is terminal for and the map induces an isomorphism .
Consider now another injective morphism of curves such that is terminal for . Assume there is a connected open subset of containing and and assume the canonical orientations on and extend to an orientation of . There is an isomorphism of curves fixing such that . It induces an isomorphism , and that isomorphism does not depend on the choice of .