Consider the following premises. q_2 <-> w_3. p_6. q_2 -> ~t. p_6 -> t. Can we infer ~w_3 from them?
 From p_6 -> t, p_6 we can infer t. From q_2 -> ~t, t we can infer ~q_2. Finally, from q_2 <-> w_3, ~q_2 we can infer ~w_3. Therefore, the answer is yes.