What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_18, x_18 will work. For all x_18, if x_18 sleeps, then x_18 is working. For all x_18, if x_18 works, then x_18 is sleeping.
For all x_18, x_18 will sleep. For all x_18, x_18 will sleep if and only if x_18 will work. For all x_18, x_18 will work if and only if x_18 will sleep.