Consider the following premises. forall z: R(z) -> W(z). forall z: W(z) -> T(z). exists z: R(z) or ~T(z). Can we infer forall z: ~(R(z) <-> T(z)) from them?
 From exists z: R(z) or ~T(z) we can infer exists z: T(z) -> R(z). From forall z: R(z) -> W(z), forall z: W(z) -> T(z) we can infer forall z: R(z) -> T(z). Finally, from forall z: R(z) -> T(z), exists z: T(z) -> R(z) we can infer exists z: R(z) <-> T(z), which contradicts forall z: ~(R(z) <-> T(z)). Therefore, the answer is no.