What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z_4, if z_4 were an office clerk, then z_4 is a mechanic. There is at least one z_4 for which z_4 is an office clerk if and only if z_4 will sleep. For all z_4, if z_4 plays a game, then z_4 is sleeping.
There is at least one z_4 for which if z_4 were an office clerk, then z_4 is sleeping. There is at least one z_4 for which if z_4 sleeps, then z_4 is an office clerk.