Prevertex of a Schwarz-Christoffel map
= Prevertex of a Schwarz-Christoffel map
= Prevertex
{synonym}
A boundary point of the source half-plane that maps to a <polygon> vertex. If that corner has angle $\pi\alpha$, the <Schwarz-Christoffel mapping> has local behavior $F(z)-F(a)\sim C(z-a)^\alpha$ at its <prevertex>, so the <derivative> has exponent $\alpha-1$. Infinity may also be a <prevertex>, expressed in the local coordinate $1/z$.