fact: Definition NSOU {X: Const} n (I: ordsysuni X n) := exists Delta sigma, Delta ⊩(n) sigma : Gamma₀' /\ (forall s t, (s, t) ∈ E₀' -> sigma • s ≡ sigma • t) /\ forall x, normal (sigma x).
imports: List Lia Morphisms Undecidability.HOU(std.std calculus.calculus unification.higher_order_unification unification.systemunification)