Consider the following premises. If it is cloudy, then Richard is an artist. If Richard were poor, then it is cloudy. For all x_12, x_12 is poor if and only if x_12 is an artist. Can we infer the following from them? If we can, name the inference rule being used: If is not true that Richard is poor if and only if Richard is an artist.
That contradicts the premises. Therefore the answer is no.