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 z: T_4(z) <-> U(z). P_1(h) <-> U(g_2). forall y_4: ~P_1(y_4).
P_1(h) -> U(g_2) can be inferred via the biconditional elimination rule. U(g_2) -> P_1(h) can be inferred via the biconditional elimination rule. forall z: T_4(z) -> U(z) can be inferred via the universal biconditional elimination rule. forall z: U(z) -> T_4(z) can be inferred via the universal biconditional elimination rule.