fact: Definition is_guarded_inj {A B: Type} (P: A -> Prop) (f: A -> B) := exists g: B -> option A, is_rev_fun P f g.
imports: Coq.Relations.Relation_Definitions Coq.Classes.Morphisms CertiGraph.lib.Coqlib CertiGraph.lib.Ensembles_ext CertiGraph.lib.Relation_ext CertiGraph.lib.Equivalence_ext CertiGraph.lib.EquivDec_ext