Consider the following premises. forall x_13: S(x_13) -> Q_2(x_13). forall x_13: S(x_13) <-> Q_12(x_13). forall x_13: Q_2(x_13) -> S(x_13). exists x_13: ~Q_12(x_13). Can we infer forall x_13: Q_2(x_13) from them?
 From forall x_13: S(x_13) -> Q_2(x_13), forall x_13: Q_2(x_13) -> S(x_13) we can infer forall x_13: S(x_13) <-> Q_2(x_13). From forall x_13: S(x_13) <-> Q_12(x_13), exists x_13: ~Q_12(x_13) we can infer exists x_13: ~S(x_13). From forall x_13: S(x_13) <-> Q_2(x_13) we can infer forall x_13: Q_2(x_13) -> S(x_13). Finally, from forall x_13: Q_2(x_13) -> S(x_13), exists x_13: ~S(x_13) we can infer exists x_13: ~Q_2(x_13), which contradicts forall x_13: Q_2(x_13). Therefore, the answer is no.