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 x_5, if x_5 were a police officer, then x_5 is playing squash. For all x_5, x_5 will drive a car if and only if x_5 will play squash. For all x_5, if x_5 plays squash, then x_5 is a police officer. For all x_5, x_5 will not drive a car.
For all x_5, x_5 is a police officer if and only if x_5 will play squash can be inferred via the universal biconditional introduction rule. For all x_5, x_5 will play squash if and only if x_5 is a police officer can be inferred via the universal biconditional introduction rule. For all x_5, if x_5 drives a car, then x_5 is playing squash can be inferred via the universal biconditional elimination rule. For all x_5, if x_5 plays squash, then x_5 is driving a car can be inferred via the universal biconditional elimination rule. For all x_5, x_5 will not play squash can be inferred via the universal biconditional elimination rule.