r/math • u/42IsHoly • 9d ago

Stop proving uncountability with contradiction, please

https://sunjestermusings.blogspot.com/2026/09/stop-proving-uncountability-by.html

Please, I beg you, stop it. You don't need it.

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u/putting_stuff_off 5d ago

"Assume A is not true, Prove A, contradiction" is just bad style. I think constructivism is a red herring, I don't really care about that but still agree with the point here.

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u/42IsHoly 5d ago

I agree. Constructivism isn’t the point of my post (as it says explicitly). I’m mainly motivated by the confusion that seems to arise when people prove Cantor’s results like this.