fact: Definition add_edge (G:sgraph) (i o : G) := {| svertex := G; sedge := add_edge_rel i o; sg_sym' := add_edge_sym_ i o; sg_irrefl' := add_edge_irrefl_ i o |}.
imports: Coq(Setoid CMorphisms) mathcomp(all_ssreflect) GraphTheory(edone preliminaries bij digraph)