Consider the following premises. p -> t. p_6 -> q_6. q_6 -> w_3. t -> w_3. p or p_6. Can we infer w_3 from them? If possible, name the inference rules being used at each step.
 From p_6 -> q_6, q_6 -> w_3 we can infer p_6 -> w_3 via transitivity. From p -> t, t -> w_3 we can infer p -> w_3 via transitivity. Finally, from p -> w_3, p_6 -> w_3, p or p_6 we can infer w_3 via disjunction elimination. Therefore, the answer is yes.