Consider the following premises. forall x_15: ~Q_15(x_15). forall x_15: U(x_15) <-> Q_4(x_15). forall x_15: U(x_15) -> T_3(x_15). exists x_15: T_3(x_15) <-> Q_15(x_15). Can we infer forall x_15: Q_4(x_15) from them?
 From exists x_15: T_3(x_15) <-> Q_15(x_15), forall x_15: ~Q_15(x_15) we can infer exists x_15: ~T_3(x_15). From forall x_15: U(x_15) -> T_3(x_15), exists x_15: ~T_3(x_15) we can infer exists x_15: ~U(x_15). Finally, from forall x_15: U(x_15) <-> Q_4(x_15), exists x_15: ~U(x_15) we can infer exists x_15: ~Q_4(x_15), which contradicts forall x_15: Q_4(x_15). Therefore, the answer is no.