I'm guessing Fermat's Last Theorem is one such case.,(reply>), Instead of an overhead cable, can the line be submerged? Maybe while anchored to a singular point in the middle of the river, and the vessel can offer up more line to combat the radial physics? The journey would be 3.14 percent faster if my calculations are correct. Damn it feels good to be smart,(reply>), ​@Cody'sLab No, it was notoriously difficult. As I remember it, not only was the written proof very long but the steps taken in the proof we individually so large that some mathematicians were sceptical that it was valid and it took quite a bit of work to verify.,(reply>), A wild cody from cody's lab... how rare!,(reply>), Harry Cruse was talking about Fermat, not Andrew Wiles. It's possible (and imo likely) that Fermat either made a mistake in his simple proof that he didn't notice, or he didn't actually a proof.,(reply>), It was published in a peer reviewed journal, and has held up to scrutiny from other experts. Not to mention he was knighted for this and received several awards.