Consider the following premises. There is at least one x_8 for which x_8 is excited if and only if x_8 is a janitor. For all x_8, x_8 is a janitor if and only if x_8 is excited. Can we infer the following from them? For all x_8, if is not true that x_8 is excited if and only if x_8 is a janitor.
That contradicts the premises. Therefore the answer is no.