What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, z will drink water if and only if z is an office clerk. There is at least one z for which if z were an office clerk, then z is drinking water. For all z, z is not an office clerk. For all z, if z were a doctor, then z is drinking water.
For all z, if z drinks water, then z is an office clerk. For all z, if z were an office clerk, then z is drinking water. For all z, z will not drink water.