fact: Fixpoint V (A: type) (s: exp X) := match A with | typevar beta => False | A → B => match s with | lambda s => normal s /\ forall t delta, C (V A) t -> C (V B) ((ren delta (lambda s)) t) | _ => False end end.
imports: Morphisms Lia Undecidability.HOU(std.std) Undecidability.HOU.calculus(prelim terms syntax semantics confluence typing order)