Mathematical folklore contains a story about how Acta Quandalia published a paper proving that all partially uniform k-quandles had the Cosell property, and then a few months later published another paper proving that no partially uniform k-quandles had the Cosell property. And in fact, goes the story, both theorems were quite true, which put a sudden end to the investigation of partially uniform k-quandles.
This sounds like a funny "blooper" story, but could just as well be an entirely normal history of the solution to an important problem. Many important theorems are proved by contradiction, and for all we know, the question of the existence of partially uniform k-quandles could have been a difficult unsolved problem.
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