Untyped "constant"?

[cis.ohio-state.edu!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplc en!ddsdx2.jhuapl.edu!gralia@ucbvax.Berkeley.EDU (Mars J. Gralia)]

I have a question about Ada.  It has to do with "named numbers" and 
their subsequent use.

a) Suppose I have a compiler/RTE in which integer'last is 32_767.
b) And suppose the system has a long_integer type in which
   long_integer'last = 2_147_483_647.
c) And suppose I have the program:
          procedure Named1 is
             X : constant := integer'last+5;
          begin
              for j in 1..X loop
                  null;
              end loop;
          end Named1;

d) Finally, suppose the "loop" variables are really used. E.g., by
   disabling optimization when I invoke the compiler.  


Then:  is this a legal program or not?


Thanks,
Mars Gralia



DISCUSSION

Some compilers, admittedly archaic or for very small computers, 
will raise a Constraint_Error, thereby forcing me to say:
             X : constant long_integer := integer'last+5;

I would prefer the program given above, because it would appear to be 
more portable.