Consider the following premises. forall x_13: R_13(x_13) and S_13(x_13). w. Can we infer ~R_13(a) from them?
 From forall x_13: R_13(x_13) and S_13(x_13) we can infer R_13(a) and S_13(a). Finally, from R_13(a) and S_13(a) we can infer R_13(a), which contradicts ~R_13(a). Therefore, the answer is no.