Consider the following premises. u -> ~q_14. ~S_11(a_11). forall x_11: R_11(x_11) <-> S_11(x_11). q_14. Can we infer ~R_11(a_11) and ~u from them? If possible, name the inference rules being used at each step.
 From u -> ~q_14, q_14 we can infer ~u via modus tollens. From forall x_11: R_11(x_11) <-> S_11(x_11) we can infer R_11(a_11) <-> S_11(a_11) via universal instantiation. From R_11(a_11) <-> S_11(a_11), ~S_11(a_11) we can infer ~R_11(a_11) via biconditional elimination. Finally, from ~R_11(a_11), ~u we can infer ~R_11(a_11) and ~u via conjunction. Therefore, the answer is yes.