Consider the following premises. forall x_5: ~R_5(x_5). R_5(f) or s. Can we infer ~s from them?
 From forall x_5: ~R_5(x_5) we can infer ~R_5(f). Finally, from R_5(f) or s, ~R_5(f) we can infer s, which contradicts ~s. Therefore, the answer is no.