What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_2, if x_2 were a mechanic, then x_2 is a cashier. For all x_2, if x_2 were a janitor, then x_2 is a mechanic. For all x_2, x_2 is not a cashier. For all x_2, if x_2 were a cashier, then x_2 is a janitor.
For all x_2, x_2 is not a mechanic. For all x_2, if x_2 were a mechanic, then x_2 is a janitor. For all x_2, if x_2 were a janitor, then x_2 is a cashier. For all x_2, if x_2 were a cashier, then x_2 is a mechanic.