Consider the following premises. If it is overcast, then it is cloudy. For all x_14, x_14 will take a plane if and only if x_14 is a politician. If it is cloudy, then Mary is a politician. Can we infer the following from them? If we can, name the inference rule being used: The fact that it is overcast does not imply that Mary is taking a plane.
That contradicts the premises. Therefore the answer is no.