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: For all z, z is a soldier or z is a nurse. For all z, z will play squash if and only if z is a nurse. For all z, z is not a soldier or z will listen to a song. For all z, z will not play squash.
For all z, z is a nurse or z will listen to a song can be inferred via the universal resolution rule. For all z, if z plays squash, then z is a nurse can be inferred via the universal biconditional elimination rule. For all z, if z were a nurse, then z is playing squash can be inferred via the universal biconditional elimination rule. For all z, z is not a nurse can be inferred via the universal biconditional elimination rule.