"Yannick Duch�ne (Hibou57)" <yannick_duchene@yahoo.fr> wrote in message 
news:op.v9bmlfrvule2fv@douda-yannick...
...
>I still can't explain the first and the second interpretation. In the 
>first case "10 ** I" seems to be interpreted as "(10 ** I) mod 256" and 
>"Natural'Pos (10 ** I)" seems not.

Yes, that's right of course. In the first case, everything has your modular 
type, in the latter case the expression has type Universal_Integer (which is 
obviously different).

Ada always prefers non-universal types, so those are only used in rare 
circumstances.

                                            Randy.