Consider the following premises. R_3(g_4) -> w. S_3(g_4) -> w. forall x_3: R_3(x_3) or S_3(x_3). Can we infer ~w from them?
 From forall x_3: R_3(x_3) or S_3(x_3) we can infer R_3(g_4) or S_3(g_4). Finally, from R_3(g_4) -> w, S_3(g_4) -> w, R_3(g_4) or S_3(g_4) we can infer w, which contradicts ~w. Therefore, the answer is no.