Final answer:
Using "If and only if" establishes a biconditional relationship, making the antecedent a necessary and sufficient condition for the consequent, and thus correcting converse errors.
Step-by-step explanation:
Prefacing the antecedent with "If and only if" corrects a converse error by establishing a biconditional relationship between the antecedent and the consequent. A conditional statement with a converse error typically has the form "If P then Q," but the error arises when one assumes the reverse is also true without proper justification ("If Q then P"). To ensure the converse is true as well, we use "If and only if" to signify that P is not only a sufficient condition for Q but also a necessary one. For instance, the statement "You will graduate if and only if you complete 120 credit hours" implies that completing 120 credit hours is both necessary and sufficient to graduate. Therefore, this biconditional rules out other possibilities that could lead to graduation without completing 120 credit hours, as well as possibilities of not graduating despite completing them.