fact: Definition ptail (g: Gph) (p: path) : path := match p with | (v, nil) => (v, nil) | (_, e :: el) => (dst g e, el) end.
imports: Coq.Logic.ProofIrrelevance Coq.micromega.Lia CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model Coq.Lists.List Coq.Lists.ListDec