What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, if z cooks, then z is drinking water. For all z, z will not drink water. For all z, if z cooks, then z is a cashier. For all z, if z were a cashier, then z is cooking.
For all z, z will not cook. For all z, if z were a cashier, then z is drinking water. For all z, z will cook if and only if z is a cashier. For all z, z is a cashier if and only if z will cook.