Consider the following premises. u_3 -> q_10. u_3. forall x_20: R_20(x_20) and S_20(x_20). Can we infer ~R_20(a_20) from them?
 From forall x_20: R_20(x_20) and S_20(x_20) we can infer R_20(a_20) and S_20(a_20). From u_3 -> q_10, u_3 we can infer q_10. Finally, from R_20(a_20) and S_20(a_20) we can infer R_20(a_20), which contradicts ~R_20(a_20). Therefore, the answer is no.