fact: Definition enum_grect r := let: Grect xmin xmax ymin ymax := r in [seq Gpoint x y | x <- zspan xmin xmax, y <- zspan ymin ymax].
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(div choice order ssralg ssrnum ssrint intdiv) fourcolor(hypermap)