Consider the following premises. q -> q_7. p <-> ~q. ~q_7. Can we infer ~p from them? If possible, name the inference rules being used at each step.
 From q -> q_7, ~q_7 we can infer ~q via modus tollens. From p <-> ~q we can infer ~q -> p via biconditional elimination. Finally, from ~q -> p, ~q we can infer p via modus ponens, which contradicts ~p. Therefore, the answer is no.