Consider the following premises. For all x_8, if x_8 writes a letter, then x_8 is working. For all x_8, if x_8 works, then x_8 is playing tennis. For all x_8, x_8 will write a letter. For all x_8, x_8 will sleep. Can we infer the following from them? If we can, name the inference rule being used: For all x_8, x_8 will write a letter.
That is one of the premises. Therefore, the answer is yes.