Consider the following premises. forall z_1: Q(z_1) and W(z_1). Q(f_2) <-> t_2. Can we infer t_2 from them?
 From forall z_1: Q(z_1) and W(z_1) we can infer Q(f_2) and W(f_2). From Q(f_2) and W(f_2) we can infer Q(f_2). From Q(f_2) <-> t_2 we can infer Q(f_2) -> t_2. Finally, from Q(f_2) -> t_2, Q(f_2) we can infer t_2. Therefore, the answer is yes.