Consider the following premises. s <-> q_7. w. s <-> t. ~t. Can we infer ~q_7 and w from them?
 From s <-> t, ~t we can infer ~s. From s <-> q_7, ~s we can infer ~q_7. Finally, from ~q_7, w we can infer ~q_7 and w. Therefore, the answer is yes.