Consider the following premises. q_1 or t_2. p_28 <-> r_4. ~r_4. t_2 -> s_2. p_5 -> p_28. q_1 -> s_2. Can we infer p_5 from them? If possible, name the inference rules being used at each step.
 From p_28 <-> r_4, ~r_4 we can infer ~p_28 via biconditional elimination. From q_1 -> s_2, t_2 -> s_2, q_1 or t_2 we can infer s_2 via disjunction elimination. Finally, from p_5 -> p_28, ~p_28 we can infer ~p_5 via modus tollens, which contradicts p_5. Therefore, the answer is no.