Conway postulated that the Steiner-Lehmus theorem is unprovable using direct methods of proof. Can this be proven directly, that the Steiner-Lehmus theorem cannot be proven directly over Euclidean postulates?

MathOverflow is a question and answer site for professional mathematicians. It's 100% free, no registration required.

`$(c-a)\{ ac^2 + (a^2+3ab+b^2)c + b^2(a+b)\} = 0$`

. – François G. Dorais♦ Jul 6 '10 at 2:58