 is truth-valueless whenever \(A\) is (unless we make negations of truth-valueless statements true) and hence becomes invalid. Of course this law and many other standard logical principles remain weakly valid—i.e., not false on any model—and it is possible to construct a logic based on weak validity rather than ordinary validity. But because any such logic will still be weaker than classical logic and because its theorems need not even be true, most logicians reject this strategy. For more on neutral free logic, see Lehman 1994, 2001, and 2002, pp. 233–237.