Consider the following premises. forall x_4: S_4(x_4). Can we infer S_4(h_2) or w from them? If possible, name the inference rules being used at each step.
 From forall x_4: S_4(x_4) we can infer S_4(h_2) via universal instantiation. Finally, from S_4(h_2) we can infer S_4(h_2) or w via addition. Therefore, the answer is yes.