Consider the following premises. forall x_17: Q(x_17) or S_17(x_17). Q(a_17) -> u. u or ~S_17(a_17). Can we infer u or s from them?
 From forall x_17: Q(x_17) or S_17(x_17) we can infer Q(a_17) or S_17(a_17). From u or ~S_17(a_17) we can infer S_17(a_17) -> u. From Q(a_17) -> u, S_17(a_17) -> u, Q(a_17) or S_17(a_17) we can infer u. Finally, from u we can infer u or s. Therefore, the answer is yes.