What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_8: U(x_8) -> S_8(x_8). ~r_4 or w_4. w_4 -> S_8(a_8). r_4 or U(a_8).
U(a_8) or w_4. R_1(a_8) -> r_4.