Consider the following premises. S_12(j) -> s_2. s_2 -> S_2(j). forall x_12: S_2(x_12) -> S_12(x_12). Can we infer s_2 -> S_12(j) from them? If possible, name the inference rules being used at each step.
 From forall x_12: S_2(x_12) -> S_12(x_12) we can infer S_2(j) -> S_12(j) via universal instantiation. Finally, from s_2 -> S_2(j), S_2(j) -> S_12(j) we can infer s_2 -> S_12(j) via transitivity. Therefore, the answer is yes.