Consider the following premises. forall x_12: P_8(x_12) or Q_8(x_12). forall x_12: Q_8(x_12) -> R_8(x_12). forall x_12: Q_4(x_12) -> P(x_12). forall x_12: P(x_12) <-> Q_12(x_12). forall x_12: Q_12(x_12) or Q_4(x_12). forall x_12: P_8(x_12) -> R_8(x_12). Can we infer forall x_12: P(x_12) and R_8(x_12) from them?
 From forall x_12: P(x_12) <-> Q_12(x_12) we can infer forall x_12: Q_12(x_12) -> P(x_12). From forall x_12: P_8(x_12) -> R_8(x_12), forall x_12: Q_8(x_12) -> R_8(x_12), forall x_12: P_8(x_12) or Q_8(x_12) we can infer forall x_12: R_8(x_12). From forall x_12: Q_12(x_12) -> P(x_12), forall x_12: Q_4(x_12) -> P(x_12), forall x_12: Q_12(x_12) or Q_4(x_12) we can infer forall x_12: P(x_12). Finally, from forall x_12: P(x_12), forall x_12: R_8(x_12) we can infer forall x_12: P(x_12) and R_8(x_12). Therefore, the answer is yes.