proposition: Lemma ζ_0P {X: config} : ζ 0 X = atom (embed (nf X)).
proof: Proof. done. Qed.
imports: List PeanoNat Lia Relations.Relation_Operators Relations.Operators_Properties Undecidability.StackMachines(SSM) Undecidability.StackMachines.Util(CSSM_facts) Undecidability.SemiUnification.SemiU Undecidability.SemiUnification.Util(Enumerable) ssreflect ssrfun ssrbool