Consider the following premises. T(a_7) -> W(a_7). forall z: T(z) <-> W(z). Can we infer T(a_7) <-> W(a_7) from them? If possible, name the inference rules being used at each step.
We can infer T(a_7) <-> W(a_7) via the universal instantiation rule. Therefore, the answer is yes.