Consider the following premises. p_11 -> u_2. p_11 or q_11. p_2 <-> w. p_2 -> ~u_2. q_11 -> u_2. Can we infer ~w from them? If possible, name the inference rules being used at each step.
 From p_11 -> u_2, q_11 -> u_2, p_11 or q_11 we can infer u_2 via disjunction elimination. From p_2 -> ~u_2, u_2 we can infer ~p_2 via modus tollens. Finally, from p_2 <-> w, ~p_2 we can infer ~w via biconditional elimination. Therefore, the answer is yes.