Consider the following premises. ~p_8. forall x_15: R_2(x_15) -> S_15(x_15). p_8 <-> u. S_15(i) <-> u. Can we infer ~R_2(i) from them? If possible, name the inference rules being used at each step.
 From forall x_15: R_2(x_15) -> S_15(x_15) we can infer R_2(i) -> S_15(i) via universal instantiation. From p_8 <-> u, ~p_8 we can infer ~u via biconditional elimination. From S_15(i) <-> u, ~u we can infer ~S_15(i) via biconditional elimination. Finally, from R_2(i) -> S_15(i), ~S_15(i) we can infer ~R_2(i) via modus tollens. Therefore, the answer is yes.