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_3, if z_3 were a scientist, then z_3 is driving a car. For all z_3, z_3 will sleep if and only if z_3 will drive a car. For all z_3, z_3 is not a scientist. For all z_3, if z_3 drives a car, then z_3 is a scientist.
For all z_3, z_3 will not drive a car can be inferred via the universal modus tollens rule. For all z_3, z_3 is a scientist if and only if z_3 will drive a car can be inferred via the universal biconditional introduction rule. For all z_3, z_3 will drive a car if and only if z_3 is a scientist can be inferred via the universal biconditional introduction rule. For all z_3, if z_3 sleeps, then z_3 is driving a car can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 drives a car, then z_3 is sleeping can be inferred via the universal biconditional elimination rule.