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 were a poet, then y is a police officer. For all y, y is a police officer if and only if y will play tennis. For all y, if y plays tennis, then y is a poet.
For all y, if y plays tennis, then y is a police officer can be inferred via the universal transitivity rule. For all y, if y were a police officer, then y is playing tennis can be inferred via the universal biconditional elimination rule. For all y, if y plays tennis, then y is a police officer can be inferred via the universal biconditional elimination rule.