Alain Frisch a écrit :
> Something that Jean-Christophe's implementation doesn't do but which is
> quite easy to add is to use hash-consing on patricia trees themselves,

This is a nice idea, thanks; I will eventually add this to my
implementation.

Meanwhile, I can mention that there is also an hash-consing library on
my web page (together with a paper describing the technique) and thus
it should be as ``simple'' as combining the two codes :-)

-- 
Jean-Christophe Filliâtre
http://www.lri.fr/~filliatr/