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 lawyer if and only if z will drive a car. For all z, z will drive a car if and only if z is a lawyer.
For all z, if z were a lawyer, then z is driving a car can be inferred via the universal biconditional elimination rule. For all z, if z drives a car, then z is a lawyer can be inferred via the universal biconditional elimination rule. For all z, if z drives a car, then z is a lawyer can be inferred via the universal biconditional elimination rule. For all z, if z were a lawyer, then z is driving a car can be inferred via the universal biconditional elimination rule.