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 is poor. For all z, z will cook if and only if z will take a plane. For all z, if z cooks, then z is not poor.
For all z, z will not cook. For all z, if z cooks, then z is taking a plane. For all z, if z takes a plane, then z is cooking.