What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: There is at least one z for which z will play squash or z is not a sailor. For all z, z is a sailor or z will not play squash.
For all z, if z plays squash, then z is a sailor can be inferred via the universal rewriting rule. There is at least one z for which if z were a sailor, then z is playing squash can be inferred via the existential rewriting rule.