Wide Character Problem in Ada.Numerics

[david.smith@gmail.com]

Hi, I'm new here and to Ada.  I'm having a problem compiling code
using greek letters as identifiers.  The problem arises when I need to
use the Ada.Numerics package.  My source code is UTF-8, and I'm
entering the characters using a greek keymap in vim.  I'm using gnat/
gcc-4.1 and the -gnatiw and -gnatW8 switches.

An example code I wrote compiles fine:
---
with Ada.Wide_Text_IO; use Ada.Wide_Text_IO;
with Ada.Float_Text_IO; use Ada.Float_Text_IO;
procedure WCTest is
   Σ : Wide_Character := 'π';
   μ : Float := 0.01;
begin
   Put(Σ);
   New_Line;
   Put(μ);
end WCTest;
---
Output:
π
 1.00000E-02
---

When I next compile my real code with greek letters *and* using the
Ada.Numerics package, I get the following error:

a-numeri.ads:25:04: illegal wide character

This is the line that has the bracket notation definition of pi in
it.

Does anyone know what is going on?  Why is there an error in a system
file?

Thanks!