What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_5, if x_5 works, then x_5 is taking a plane. For all x_5, if x_5 takes a plane, then x_5 is working. For all x_5, x_5 will not work. For all x_5, x_5 will take a plane or x_5 is a cashier.
For all x_5, x_5 will not take a plane. For all x_5, x_5 will work if and only if x_5 will take a plane. For all x_5, x_5 will take a plane if and only if x_5 will work.