> It seems that it is sufficient to define
>
>         let add a b = List.map2 R.add a b
>
> instead of
>
>         let add = List.map2 R.add
>
> to make the segmentation fault disappear (Ocaml 3.09.1).

That is besides the point =P The fact is that the code -does- segfault
while there is nothing syntactically (and probably semanticly) wrong
with the code.

Jonathan