Consider the following premises. forall x_8: P_8(x_8) <-> Q(x_8). forall x_8: Q_1(x_8). forall x_8: P_5(x_8) -> Q(x_8). forall x_8: P_5(x_8) or P_8(x_8). Can we infer exists x_8: ~Q_1(x_8) from them?
 From forall x_8: P_8(x_8) <-> Q(x_8) we can infer forall x_8: P_8(x_8) -> Q(x_8). From forall x_8: P_5(x_8) -> Q(x_8), forall x_8: P_8(x_8) -> Q(x_8), forall x_8: P_5(x_8) or P_8(x_8) we can infer forall x_8: Q(x_8). From forall x_8: Q(x_8), forall x_8: Q_1(x_8) we can infer forall x_8: Q(x_8) and Q_1(x_8). Finally, from forall x_8: Q(x_8) and Q_1(x_8) we can infer forall x_8: Q(x_8), which contradicts exists x_8: ~Q_1(x_8). Therefore, the answer is no.