Lemme 1

Any increasing function is derivable.
A counter-exemple later...

Lemme 2

Any increasing function is derivable except on a finite number of points.
A counter-exemple later...

Lemme 3

Any increasing function is derivable except on a denombrable number of points.
A counter-exemple later...

Bull shit !

It was the end of the famous lemmes of Rossin.

[E-mail] [Edd]