Consider the following premises. forall x_7: S(x_7) <-> U_2(x_7). forall x_7: U_2(x_7) and Q_7(x_7). Can we infer forall x_7: S(x_7) from them? If possible, name the inference rules being used at each step.
 From forall x_7: U_2(x_7) and Q_7(x_7) we can infer forall x_7: U_2(x_7) via universal simplification. From forall x_7: S(x_7) <-> U_2(x_7) we can infer forall x_7: U_2(x_7) -> S(x_7) via universal biconditional elimination. Finally, from forall x_7: U_2(x_7) -> S(x_7), forall x_7: U_2(x_7) we can infer forall x_7: S(x_7) via universal modus ponens. Therefore, the answer is yes.