Consider the following premises. For all x_5, if x_5 writes a letter, then x_5 is running. For all x_5, x_5 is an artist or x_5 will write a letter. For all x_5, x_5 is a police officer. For all x_5, if x_5 were an artist, then x_5 is running. Can we infer the following from them? If we can, name the inference rule being used: For all x_5, x_5 is a police officer.
That is one of the premises. Therefore, the answer is yes.