fact: Fixpoint action (f : X -> X) u := match u with | Def.Var x => Var (f x) | Def.Fun f => Fun f | Def.App u1 u2 => App (action f u1) (action f u2) | Def.Lam x v => Lam (f x) (action f v) end.
imports: CoLoR(LogicUtil LAlpha RelUtil BoolUtil) Coq(Morphisms)