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_1: U_4(x_1) -> Q(x_1). t_4 or U_4(g_2). forall x_1: Q(x_1) -> U_4(x_1). t_4 -> Q(g_2).
R_1(g_2) -> t_4 can be inferred via the rewriting rule. forall x_1: U_4(x_1) <-> Q(x_1) can be inferred via the universal biconditional introduction rule. forall x_1: Q(x_1) <-> U_4(x_1) can be inferred via the universal biconditional introduction rule.