Consider the following premises. ~q_1. p -> p_1. p_6 -> q_1. p_1 <-> p_6. Can we infer ~p from them? If possible, name the inference rules being used at each step.
 From p_6 -> q_1, ~q_1 we can infer ~p_6 via modus tollens. From p_1 <-> p_6, ~p_6 we can infer ~p_1 via biconditional elimination. Finally, from p -> p_1, ~p_1 we can infer ~p via modus tollens. Therefore, the answer is yes.