Consider the following premises. forall x_17: T(x_17) <-> Q_17(x_17). forall x_17: Q_17(x_17). Can we infer T(a_9) or q from them? If possible, name the inference rules being used at each step.
 From forall x_17: T(x_17) <-> Q_17(x_17) we can infer forall x_17: Q_17(x_17) -> T(x_17) via universal biconditional elimination. From forall x_17: Q_17(x_17) -> T(x_17), forall x_17: Q_17(x_17) we can infer forall x_17: T(x_17) via universal modus ponens. From forall x_17: T(x_17) we can infer T(a_9) via universal instantiation. Finally, from T(a_9) we can infer T(a_9) or q via addition. Therefore, the answer is yes.