Consider the following premises. forall x_13: P_13(x_13). forall x_13: P_13(x_13) -> Q_13(x_13). forall x_13: P_12(x_13). Can we infer P_12(a_11) or s_2 from them?
 From forall x_13: P_13(x_13) -> Q_13(x_13), forall x_13: P_13(x_13) we can infer forall x_13: Q_13(x_13). From forall x_13: P_12(x_13), forall x_13: Q_13(x_13) we can infer forall x_13: P_12(x_13) and Q_13(x_13). From forall x_13: P_12(x_13) and Q_13(x_13) we can infer P_12(a_11) and Q_13(a_11). From P_12(a_11) and Q_13(a_11) we can infer P_12(a_11). Finally, from P_12(a_11) we can infer P_12(a_11) or s_2. Therefore, the answer is yes.