fact: Variable (X : Type) (HX : exists l, forall x : X, x ∊ l) (R : X -> X -> Prop) (Rirrefl : forall x, ~ R x x) (Rtrans : forall x y z, R x y -> R y z -> R x z).
imports: Arith List Lia Undecidability.Shared.Libs.DLW.Utils(php) Undecidability.Shared.Libs.DLW.Wf(wf_chains)