Consider the following premises. P_5(g). forall x_5: P_5(x_5) <-> Q(x_5). Can we infer forall x_5: ~Q(x_5) from them?
 From P_5(g) we can infer exists x_5: P_5(x_5). From forall x_5: P_5(x_5) <-> Q(x_5) we can infer forall x_5: P_5(x_5) -> Q(x_5). Finally, from forall x_5: P_5(x_5) -> Q(x_5), exists x_5: P_5(x_5) we can infer exists x_5: Q(x_5), which contradicts forall x_5: ~Q(x_5). Therefore, the answer is no.