Consider the following premises. For all x_4, x_4 will sleep or x_4 is a writer. For all x_4, if x_4 were a writer, then x_4 is sad. For all x_4, if x_4 sleeps, then x_4 is sad. Can we infer the following from them? If we can, name the inference rule being used: For all x_4, if x_4 were a writer, then x_4 is sad.
That is one of the premises. Therefore, the answer is yes.