Consider the following premises. For all x_3, if x_3 were happy, then x_3 is a nurse. For all x_3, if x_3 were happy, then x_3 is a poet. For all x_3, if x_3 were a nurse, then x_3 is happy. There is at least one x_3 for which x_3 is not a poet. Can we infer the following from them? If we can, name the inference rule being used: For all x_3, if x_3 were happy, then x_3 is a poet.
That is one of the premises. Therefore, the answer is yes.