Consider the following premises. forall y_2: R(y_2) <-> S(y_2). forall y_2: Q(y_2) -> S(y_2). forall y_2: R_1(y_2). forall y_2: R(y_2) or Q(y_2). Can we infer forall y_2: R_1(y_2) and S(y_2) from them? If possible, name the inference rules being used at each step.
 From forall y_2: R(y_2) <-> S(y_2) we can infer forall y_2: R(y_2) -> S(y_2) via universal biconditional elimination. From forall y_2: R(y_2) -> S(y_2), forall y_2: Q(y_2) -> S(y_2), forall y_2: R(y_2) or Q(y_2) we can infer forall y_2: S(y_2) via universal disjunction elimination. Finally, from forall y_2: R_1(y_2), forall y_2: S(y_2) we can infer forall y_2: R_1(y_2) and S(y_2) via universal conjunction. Therefore, the answer is yes.