Consider the following premises. forall x_14: ~R_14(x_14). ~u -> t. u -> R_14(a_14). Can we infer t from them? If possible, name the inference rules being used at each step.
 From forall x_14: ~R_14(x_14) we can infer ~R_14(a_14) via universal instantiation. From u -> R_14(a_14), ~R_14(a_14) we can infer ~u via modus tollens. Finally, from ~u -> t, ~u we can infer t via modus ponens. Therefore, the answer is yes.