Does anybody know how to obtain quickly in closed form the functional inverse, denoted by Inv(a, b, c ; x) , of the Gauss hypergeometric function ( in Maple notation) hypergeom( [a, b], [c], x), satisfying hypergeom( [a, b], [c], Inv(a, b, c ; x) ) = x ? Thanks in advance, Karol A. Penson