Consider the following premises. forall x_17: ~R_17(x_17). u_4 <-> R_17(h). u_4. Can we infer p_2 from them? If possible, name the inference rules being used at each step.
 From forall x_17: ~R_17(x_17) we can infer ~R_17(h) via universal instantiation. From u_4 <-> R_17(h), ~R_17(h) we can infer ~u_4 via biconditional elimination. From ~u_4 we can infer ~u_4 or p_2 via addition. Finally, from ~u_4 or p_2, u_4 we can infer p_2 via disjunctive syllogism. Therefore, the answer is yes. Notice, however, that the premises were contradictory, so we can infer anything from them.