fact: Hypothesis abcm0P : forall e i, ab_cm_proper ab0 cm0 e i.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph order ssralg ssrnum ssrint) fourcolor(hypermap geometry color coloring patch snip grid) fourcolor(matte)