Consider the following premises. forall x_6: Q_6(x_6) -> P_6(x_6). forall x_6: P_6(x_6) <-> Q_6(x_6). Can we infer Q_6(i) -> P_6(i) from them?
 From forall x_6: P_6(x_6) <-> Q_6(x_6) we can infer forall x_6: P_6(x_6) -> Q_6(x_6). From forall x_6: P_6(x_6) -> Q_6(x_6), forall x_6: Q_6(x_6) -> P_6(x_6) we can infer forall x_6: P_6(x_6) <-> Q_6(x_6). From forall x_6: P_6(x_6) <-> Q_6(x_6) we can infer P_6(i) <-> Q_6(i). Finally, from P_6(i) <-> Q_6(i) we can infer Q_6(i) -> P_6(i). Therefore, the answer is yes.