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: Joseph is driving a car if and only if Joseph is happy. For all y_3, if y_3 drives a car, then y_3 is happy. Joseph is not driving a car.
If Joseph drives a car, then Joseph is happy can be inferred via the biconditional elimination rule. If Joseph were happy, then Joseph is driving a car can be inferred via the biconditional elimination rule.