> I don't know why you have "proofs" in quotation marks Because proof by contradiction is viewed by an entire category of mathematicians as "wrong" (please mak

> I don't know why you have "proofs" in quotation marks Because proof by contradiction is viewed by an entire category of mathematicians as "wrong" (please make sure to note the use of quotes in case you missed them). Read all about it here: https://en.wikipedia.org/wiki/Constructivism_(philosophy_of_mathematics) https://en.wikipedia.org/wiki/Constructivism_(philosophy_of_... In a very tangible sense, they're correct. "Proof" by contradiction, tertium non datur, proof by the absurd, whatever you want to call it, more often than not entirely fails to produce working examples, which makes the "proof" fare less useful than the one that explains how to build an actual exemplar.