Consider the following premises. forall x_11: P_11(x_11) <-> Q_11(x_11). forall x_11: P_11(x_11) <-> Q_11(x_11). Can we infer Q_11(c_3) -> P_11(c_3) from them?
 From forall x_11: P_11(x_11) <-> Q_11(x_11) we can infer forall x_11: Q_11(x_11) -> P_11(x_11). From forall x_11: P_11(x_11) <-> Q_11(x_11) we can infer forall x_11: P_11(x_11) -> Q_11(x_11). From forall x_11: Q_11(x_11) -> P_11(x_11), forall x_11: P_11(x_11) -> Q_11(x_11) we can infer forall x_11: Q_11(x_11) <-> P_11(x_11). From forall x_11: Q_11(x_11) <-> P_11(x_11) we can infer Q_11(c_3) <-> P_11(c_3). Finally, from Q_11(c_3) <-> P_11(c_3) we can infer Q_11(c_3) -> P_11(c_3). Therefore, the answer is yes.