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 play squash if and only if z will drink water. For all z, if z drinks water, then z is playing squash. For all z, if z plays squash, then z is drinking water.
For all z, z will drink water if and only if z will play squash. For all z, z will play squash if and only if z will drink water. For all z, if z plays squash, then z is drinking water. For all z, if z drinks water, then z is playing squash.