proposition: Lemma erase_P_W : erase P_W = M_W.
proof: Proof. by rewrite /P_W /= erase_many_ty_abs /= /x_1_W /x_2_W ?erase_many_ty_app. Qed.
imports: List Lia Undecidability.SystemF.SysF Undecidability.SystemF.Autosubst.syntax Undecidability.SystemF.Util(Facts poly_type_facts pure_term_facts term_facts typing_facts pure_typing_facts pure_typable_prenex) ssreflect ssrbool ssrfun