fact: Definition mark (g1 : Graph) (root : V) (g2 : Graph) : Prop := g1 ~=~ g2 /\ (forall n, g1 |= root ~o~> n satisfying (unmarked g1) -> marked g2 n) /\ (forall n, ~ g1 |= root ~o~> n satisfying (unmarked g1) -> (marked g1 n <-> marked g2 n)).
imports: Coq.Logic.ProofIrrelevance CertiGraph.lib.Ensembles_ext Coq.Lists.List Coq.Classes.Morphisms CertiGraph.lib.Coqlib CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext VST.msl.Coqlib2 CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.reachable_computable CertiGraph.graph.reachable_ind CertiGraph.graph.graph_gen CertiGraph.graph.graph_relation CertiGraph.graph.subgraph2