Consider the following premises. ~q_7. p -> r_4. r_4 -> t. t -> q_7. Can we infer p from them? If possible, name the inference rules being used at each step.
 From t -> q_7, ~q_7 we can infer ~t via modus tollens. From r_4 -> t, ~t we can infer ~r_4 via modus tollens. Finally, from p -> r_4, ~r_4 we can infer ~p via modus tollens, which contradicts p. Therefore, the answer is no.