What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_15: ~P_15(x_15) or U(x_15). forall x_15: ~U_2(x_15). p -> ~U(f_4). forall x_15: P_15(x_15) or U_2(x_15).
forall x_15: U_2(x_15) or U(x_15).