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 y, if y works, then y is playing squash. For all y, y is a police officer if and only if y will play squash. There is at least one y for which y will work or y is a police officer.
For all y, if y were a police officer, then y is playing squash can be inferred via the universal biconditional elimination rule. For all y, if y plays squash, then y is a police officer can be inferred via the universal biconditional elimination rule.