What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y: Q(y) or ~P_4(y). forall y: P(y) -> P_4(y). forall y: Q(y) <-> U_1(y). forall y: ~U_1(y). exists y: Q(y) -> P(y).
exists y: Q(y) -> P_4(y). forall y: P_4(y) -> Q(y). forall y: Q(y) -> U_1(y). forall y: U_1(y) -> Q(y). forall y: ~Q(y).