What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, x_9 is a janitor if and only if x_9 is a poet. For all x_9, x_9 is a poet if and only if x_9 is a janitor. For all x_9, x_9 is not a janitor.
For all x_9, if x_9 were a janitor, then x_9 is a poet. For all x_9, if x_9 were a poet, then x_9 is a janitor. For all x_9, if x_9 were a poet, then x_9 is a janitor. For all x_9, if x_9 were a janitor, then x_9 is a poet. For all x_9, x_9 is not a poet. For all x_9, x_9 is not a poet.