Consider the following premises. exists x_6: P(x_6). forall x_6: Q_6(x_6) -> R_4(x_6). forall x_6: R_6(x_6) -> R_4(x_6). forall x_6: ~P_6(x_6) or R_6(x_6). forall x_6: P_6(x_6) or Q_6(x_6). Can we infer forall x_6: ~(P(x_6) and R_4(x_6)) from them?
 From forall x_6: P_6(x_6) or Q_6(x_6), forall x_6: ~P_6(x_6) or R_6(x_6) we can infer forall x_6: Q_6(x_6) or R_6(x_6). From forall x_6: Q_6(x_6) -> R_4(x_6), forall x_6: R_6(x_6) -> R_4(x_6), forall x_6: Q_6(x_6) or R_6(x_6) we can infer forall x_6: R_4(x_6). Finally, from exists x_6: P(x_6), forall x_6: R_4(x_6) we can infer exists x_6: P(x_6) and R_4(x_6), which contradicts forall x_6: ~(P(x_6) and R_4(x_6)). Therefore, the answer is no.