Consider the following premises. ~w_2. S_19(a_19) <-> w_2. forall x_19: R_19(x_19) -> S_19(x_19). Can we infer ~R_19(a_19) or u from them?
 From forall x_19: R_19(x_19) -> S_19(x_19) we can infer R_19(a_19) -> S_19(a_19). From S_19(a_19) <-> w_2, ~w_2 we can infer ~S_19(a_19). From R_19(a_19) -> S_19(a_19), ~S_19(a_19) we can infer ~R_19(a_19). Finally, from ~R_19(a_19) we can infer ~R_19(a_19) or u. Therefore, the answer is yes.