index range while type (seemingly defined) to always include this particular value

[Mehdi Saada <00120260a@gmail.com>]

This line: 	PUT(POLY.COEF(0));
raises Constraint Error: index check failed. I can't get my head round about this.
Each time the function
See below: 0 is ALWAYS in the index range of COEF, which is an array component.

generic formal parameters:
type T_DEGRE_BASE is range <>;
MAX: in T_DEGRE_BASE;

type definitions:
subtype T_DEGRE is T_DEGRE_BASE range -MAX..MAX;
type T_Vect_Coef is array (T_Degr
type T_Polynome (Degre : T_Degre := 0) is 
    record
        COEF : T_Vect_Coef (0..Degre) := (others => NULL_ELEMENT);
    end record;e range <>) of ELEMENT;

And the actual generic parameters:
package RAT is new P_RATIONNELS_G(T_ENTIER => INTEGER);
package POLY is new P_POLY_V1_G(T_DEGRE_BASE => INTEGER,
   ELEMENT => RAT.T_RATIONNEL, NULL_ELEMENT => RAT.NULLE, MAX => 10, PUT => RAT_IO.PUT);
Lastly: 
subtype T_Entier_Pos is T_Entier range 1..T_Entier'Last;
type T_Rationnel is record
    Numerateur  : T_Entier  := 0;
    Denominateur: T_Entier_Pos := 1;
end record;