Consider the following premises. For all x_3, x_3 is an office clerk. For all x_3, x_3 will not take a plane. For all x_3, if x_3 were an office clerk, then x_3 is taking a plane. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_3 for which x_3 will not go running.
The premises are contradictory and we can infer anything from them. Therefore, the answer is yes.