What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y_1: U_2(y_1) <-> W_4(y_1). exists y_1: U_2(y_1) <-> S(y_1).
forall y_1: U_2(y_1) -> W_4(y_1). exists y_1: U_2(y_1) -> S(y_1). forall y_1: W_4(y_1) -> U_2(y_1). exists y_1: S(y_1) -> U_2(y_1).