Consider the following premises. forall x_17: S_4(x_17) or S_17(x_17). S_17(a_17) -> p_13. p_13 <-> S_4(a_17). Can we infer p_13 or q from them?
 From forall x_17: S_4(x_17) or S_17(x_17) we can infer S_4(a_17) or S_17(a_17). From p_13 <-> S_4(a_17) we can infer S_4(a_17) -> p_13. From S_4(a_17) -> p_13, S_17(a_17) -> p_13, S_4(a_17) or S_17(a_17) we can infer p_13. Finally, from p_13 we can infer p_13 or q. Therefore, the answer is yes.