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 plays squash, then z is playing tennis. For all z, z will not play squash. There is at least one z for which if z plays tennis, then z is playing squash.
There is at least one z for which z will not play tennis. There is at least one z for which z will play tennis if and only if z will play squash. There is at least one z for which z will play squash if and only if z will play tennis.