Consider the following premises. forall x_11: P_9(x_11) <-> P_11(x_11). forall x_11: Q_11(x_11). forall x_11: P_11(x_11) -> ~Q_11(x_11). p -> P_9(f). Can we infer p from them?
 From forall x_11: P_11(x_11) -> ~Q_11(x_11), forall x_11: Q_11(x_11) we can infer forall x_11: ~P_11(x_11). From forall x_11: P_9(x_11) <-> P_11(x_11), forall x_11: ~P_11(x_11) we can infer forall x_11: ~P_9(x_11). From forall x_11: ~P_9(x_11) we can infer ~P_9(f). Finally, from p -> P_9(f), ~P_9(f) we can infer ~p, which contradicts p. Therefore, the answer is no.