computation of conformal maps to polygonally bounded regions

				function Mi = inv(M)
				%INV    Inverse SC map object.
				%   INV(M) returns an object formally representing the inverse of the
				%   map M. 
				
				%   Copyright 1998 by Toby Driscoll.
				%   $Id: inv.m 7 1998-05-10 04:37:19Z tad $
				
				Mi = scmapinv(M);