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: Charles is cooking if and only if it is late. It is snowing if and only if Charles is cooking. If it snows, then Sarah is not driving a car. Sarah is driving a car.
It is not snowing can be inferred via the modus tollens rule. If Charles cooks, then it is late can be inferred via the biconditional elimination rule. If it snows, then Charles is cooking can be inferred via the biconditional elimination rule. If it is late, then Charles is cooking can be inferred via the biconditional elimination rule. If Charles cooks, then it is snowing can be inferred via the biconditional elimination rule.