Does anybody know of a fast data structure for (applicative)
association tables over ordered types (like Map in the standard
library) with the property that identical maps will have an identical
representation?  Sorted association lists work, but have linear access
and insertion.  Is there something logarithmical (even with an OCaml
implementation)?

Thanks,
-Thorsten

[ If anybody wonders: I want/need polymorphic comparison, because the
  Maps are part of a recursive datastructure. ]
-- 
Thorsten Ohl, Physics Department, TU Darmstadt -- ohl@hep.tu-darmstadt.de
http://heplix.ikp.physik.tu-darmstadt.de/~ohl/ [<=== PGP public key here]