Consider the following premises. w -> t_1. t_1 -> q_4. q_4 <-> w. w -> t_1. Can we infer ~(t_1 <-> w) from them?
 From q_4 <-> w we can infer q_4 -> w. From t_1 -> q_4, q_4 -> w we can infer t_1 -> w. Finally, from t_1 -> w, w -> t_1 we can infer t_1 <-> w, which contradicts ~(t_1 <-> w). Therefore, the answer is no.