Consider the following premises. R_7(a_7) -> P(i). forall x_7: R_7(x_7) <-> S_7(x_7). forall z: W(z) <-> P(z). ~W(i). Can we infer ~S_7(a_7) from them? If possible, name the inference rules being used at each step.
 From forall z: W(z) <-> P(z) we can infer W(i) <-> P(i) via universal instantiation. From W(i) <-> P(i), ~W(i) we can infer ~P(i) via biconditional elimination. From forall x_7: R_7(x_7) <-> S_7(x_7) we can infer R_7(a_7) <-> S_7(a_7) via universal instantiation. From R_7(a_7) -> P(i), ~P(i) we can infer ~R_7(a_7) via modus tollens. Finally, from R_7(a_7) <-> S_7(a_7), ~R_7(a_7) we can infer ~S_7(a_7) via biconditional elimination. Therefore, the answer is yes.