fact: Fixpoint Fix_F (x : A) (a : Acc x) : P x := step x (fun y r => Fix_F y (Acc_inv a y r)).
imports: Coq(Extraction CRelationClasses) Equations.Init Equations.CoreTactics Equations.Type.Logic Equations.Type.FunctionalExtensionality Equations.Type.Relation Equations.Type.Relation_Properties