What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: forall y_3: P_4(y_3). forall y_3: T_2(y_3) -> P_4(y_3). forall y_3: P_4(y_3) -> T_2(y_3).
forall y_3: T_2(y_3) can be inferred via the universal modus ponens rule. forall y_3: T_2(y_3) <-> P_4(y_3) can be inferred via the universal biconditional introduction rule. forall y_3: P_4(y_3) <-> T_2(y_3) can be inferred via the universal biconditional introduction rule.