Consider the following premises. forall x_15: ~Q_13(x_15). forall x_15: ~P_15(x_15) or R_15(x_15). forall x_15: U_2(x_15) -> ~R_15(x_15). forall x_15: Q_15(x_15) <-> Q_13(x_15). exists x_15: P_15(x_15) or Q_15(x_15). Can we infer exists x_15: ~U_2(x_15) from them?
 From exists x_15: P_15(x_15) or Q_15(x_15), forall x_15: ~P_15(x_15) or R_15(x_15) we can infer exists x_15: Q_15(x_15) or R_15(x_15). From forall x_15: Q_15(x_15) <-> Q_13(x_15), forall x_15: ~Q_13(x_15) we can infer forall x_15: ~Q_15(x_15). From exists x_15: Q_15(x_15) or R_15(x_15), forall x_15: ~Q_15(x_15) we can infer exists x_15: R_15(x_15). Finally, from forall x_15: U_2(x_15) -> ~R_15(x_15), exists x_15: R_15(x_15) we can infer exists x_15: ~U_2(x_15). Therefore, the answer is yes.