Hello everybody,

Thanks for your help.
I now have 2 solutions that should work
(it will take a couple of days to change my **real**
project to see if it works).

However, I still did not understand this statement of
Jeremy Yallop:
>> module type Abc =
>>    functor (M:Simple) ->
>>    sig
>>       val x : M.t
>>    end
>>      
> You're trying to treat Abc as a functor from signatures to signatures
> (i.e. as a parameterised signature). In fact, it's something quite
> different: it's the *type* of a functor from structures to structures.
>    
If I understand well, what I try to do is impossible for
some deep theoretical reason. Can someone explain this
to me, or point me to a relevant paper explaining it?

Yours,
Jacky