Consider the following premises. There is at least one x_15 for which if x_15 drinks water, then x_15 is a janitor. For all x_15, if x_15 were a janitor, then x_15 is not a mechanic. For all x_15, x_15 will drink water if and only if x_15 is a poet. For all x_15, if x_15 drinks water, then x_15 is a poet. For all x_15, x_15 is a mechanic. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_15 for which if x_15 drinks water, then x_15 is a janitor.
That is one of the premises. Therefore, the answer is yes.