 In K3 and Ł\(_3\) a formula \(A\) and its negation \(\osim A\) cannot both be true in the sense of both taking the designated value 1, but they both fail to be true if \(A\) receives the value \(i\), respectively \(\frac{1}{2}\). If a contrary pair of formulas is defined as a pair of formulas that cannot both be true but may both fail to be true, then Kleene negation gives rise to contrary pairs.