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_10, if x_10 sleeps, then x_10 is driving a car. For all x_10, if x_10 drives a car, then x_10 is sleeping. If Charles sleeps, then Charles is driving a car.
For all x_10, x_10 will sleep if and only if x_10 will drive a car can be inferred via the universal biconditional introduction rule. For all x_10, x_10 will drive a car if and only if x_10 will sleep can be inferred via the universal biconditional introduction rule.