What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_4, if x_4 were a janitor, then x_4 is taking a plane. For all x_4, x_4 is not a mechanic or x_4 is a janitor. For all x_4, if x_4 were a lawyer, then x_4 is taking a plane. For all x_4, x_4 will not play squash or x_4 is a lawyer. For all x_4, x_4 is a mechanic or x_4 will play squash.
For all x_4, x_4 will play squash or x_4 is a janitor.