Consider the following premises. p_4 <-> P_14(b). forall x_14: P_14(x_14). Can we infer p_4 from them?
 From forall x_14: P_14(x_14) we can infer P_14(b). From p_4 <-> P_14(b) we can infer P_14(b) -> p_4. Finally, from P_14(b) -> p_4, P_14(b) we can infer p_4. Therefore, the answer is yes.