Consider the following premises. ~p_3. w -> p_6. p_3 <-> w. p_6 -> w. Can we infer ~p_6 from them? If possible, name the inference rules being used at each step.
 From p_6 -> w, w -> p_6 we can infer p_6 <-> w via biconditional introduction. From p_3 <-> w, ~p_3 we can infer ~w via biconditional elimination. Finally, from p_6 <-> w, ~w we can infer ~p_6 via biconditional elimination. Therefore, the answer is yes.