fact: Definition decode_subst (sigma: fin -> exp ag) (N: forall x, normal (sigma x)) (x: fin) := match dec_enc (N (F x)) with | inl (exist _ n _) => n | inr _ => 0 end.
imports: RelationClasses Morphisms Init.Wf List Lia Init.Nat Setoid Undecidability.HOU(calculus.calculus unification.unification)