proposition: Fact erase_many_ty_app {ts P} : erase (many_ty_app P ts) = erase P.
proof: Proof. elim: ts P; [done | by move=> > + ? /= => ->]. Qed.
imports: List Lia Undecidability.SystemF.SysF Undecidability.SystemF.Autosubst.syntax Undecidability.SystemF.Autosubst.unscoped Undecidability.SystemF.Util(Facts poly_type_facts pure_term_facts) ssreflect ssrbool ssrfun