Consider the following premises. forall z_2: W(z_2) -> R_1(z_2). forall z_2: R_1(z_2) -> W(z_2). forall z_2: R_1(z_2) -> W(z_2). Can we infer exists z_2: ~(R_1(z_2) -> W(z_2)) from them? If possible, name the inference rules being used at each step.
 From forall z_2: R_1(z_2) -> W(z_2), forall z_2: W(z_2) -> R_1(z_2) we can infer forall z_2: R_1(z_2) <-> W(z_2) via universal biconditional introduction. From forall z_2: R_1(z_2) <-> W(z_2) we can infer forall z_2: W(z_2) -> R_1(z_2) via universal biconditional elimination. From forall z_2: W(z_2) -> R_1(z_2), forall z_2: R_1(z_2) -> W(z_2) we can infer forall z_2: W(z_2) <-> R_1(z_2) via universal biconditional introduction. Finally, from forall z_2: W(z_2) <-> R_1(z_2) we can infer forall z_2: R_1(z_2) -> W(z_2) via universal biconditional elimination, which contradicts exists z_2: ~(R_1(z_2) -> W(z_2)). Therefore, the answer is no.