Global maximum of ?(x)-x : local maximum between .42 and .5

[Joseph Biberstine]

Gerald McGarvey wrote:
> This web page (a rough, unfinished draft that might contain errors):
> http://www.linas.org/math/chap-minkowski/chap-minkowski.html
> made me start to realize how deep this function is (I only understand 
> some of it).
> This function is a real beauty.
> 
> It does seem to be of considerable interest and worthy of effort to 
> pursue this.
> 
> - Gerald

I couldn't agree more.  As one interested particularly in continued 
fractions, Minkowski's function is a truly brilliant gem.

The game-theoretic flavor of the continued fraction expansions at 
extrema of ?(x)-x is, I feel, but one minor tasty facet.

- Joseph