> It's what I was afraid of.
> I got it. Anyway let me make a consideration: It would be nice to have a 
> way (a fake module named Core,for example) to access the core types, 
> exception and definitions in case someone shadows the original one.

Why not, but frankly, I am not sure this can be done easily. Besides,
this would potentially break user code, for users who happen to have a
module named 'Core'.


> 
> exception Prim_Failure = Failure
> 
> to get rid of any further shadowing.
Good point which I missed.

As a conclusion, it is clear that the management of the so-called
'built-ins' is somehow unfortunate, and that perhaps, not all built-ins,
need to be so.

However the behavior is properly documented and workarounds are available.




Luc Maranget