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 x_12: P_2(x_12). exists x_12: T_3(x_12). forall x_12: T_3(x_12) <-> S(x_12).
exists x_12: T_3(x_12) and P_2(x_12) can be inferred via the existential conjunction rule. exists x_12: P_2(x_12) and T_3(x_12) can be inferred via the existential conjunction rule. forall x_12: T_3(x_12) -> S(x_12) can be inferred via the universal biconditional elimination rule. forall x_12: S(x_12) -> T_3(x_12) can be inferred via the universal biconditional elimination rule.