fact: Definition vertex_prop_coincide (g1 g2: PreGraph Vertex Edge) (p1 p2: Vertex -> Prop) := forall x, vvalid g1 x -> vvalid g2 x -> (p1 x <-> p2 x).
imports: Coq.Logic.ProofIrrelevance CertiGraph.lib.Ensembles_ext CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.lib.relation_list CertiGraph.lib.Equivalence_ext