fact: Definition ab_mr_proper (b : srect) e i := gr_proper b.2 -> let m0i := m0 (mr i) in [/\ i \in e -> meet (inset_srect b) m0i & meet b m0i -> i \in e].
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)