Consider the following premises. There is at least one x_6 for which if x_6 were rich, then x_6 is a janitor. For all x_6, x_6 is rich if and only if x_6 is a janitor. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_6 for which if x_6 were rich, then x_6 is a janitor.
That is one of the premises. Therefore, the answer is yes.