Consider the following premises. exists x_8: P(x_8) <-> P_1(x_8). forall x_8: ~Q_8(x_8). forall x_8: P_8(x_8) <-> Q_8(x_8). forall x_8: P_1(x_8) -> P_8(x_8). Can we infer forall x_8: ~Q_8(x_8) from them?
That is one of the premises. Therefore, the answer is yes.