What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: R_4(z) -> Q_3(z). forall x_15: R_15(x_15) -> S_15(x_15). R_15(a_15) <-> Q_3(g_3). ~S_15(a_15).
R_15(a_15) -> Q_3(g_3). Q_3(g_3) -> R_15(a_15).