fact: Definition diso_plane_embedding (G H : sgraph) (g : plane_embedding G) (i : diso G H) := Build_plane_embedding (diso_embedding g i) (emb_planar g).
imports: mathcomp(all_ssreflect) fourcolor(hypermap geometry color coloring walkup combinatorial4ct cfmap) GraphTheory(edone preliminaries bij digraph sgraph) GraphTheory(connectivity minor hmap_ops smerge hcycle arc)