Consider the following premises. ~s or r_11. p -> ~r_11. s or U_1(a_17). forall x: ~U_1(x). Can we infer p from them? If possible, name the inference rules being used at each step.
 From forall x: ~U_1(x) we can infer ~U_1(a_17) via universal instantiation. From s or U_1(a_17), ~s or r_11 we can infer U_1(a_17) or r_11 via resolution. From U_1(a_17) or r_11, ~U_1(a_17) we can infer r_11 via disjunctive syllogism. Finally, from p -> ~r_11, r_11 we can infer ~p via modus tollens, which contradicts p. Therefore, the answer is no.