fact: Hypothesis abP : forall e i, ab_mr_proper (ab e) e i.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph bigop ssralg ssrnum ssrint) mathcomp(div intdiv) fourcolor(hypermap geometry coloring grid matte gridmap) fourcolor(real realplane realprop approx)