Consider the following premises. forall x_15: P_15(x_15) -> Q_15(x_15). t <-> P_15(a). forall x_15: ~Q_15(x_15). Can we infer ~t or s from them?
 From forall x_15: P_15(x_15) -> Q_15(x_15), forall x_15: ~Q_15(x_15) we can infer forall x_15: ~P_15(x_15). From forall x_15: ~P_15(x_15) we can infer ~P_15(a). From t <-> P_15(a), ~P_15(a) we can infer ~t. Finally, from ~t we can infer ~t or s. Therefore, the answer is yes.