DATE     94/01/10
 
    Opérateur SIMPLEX
    -----------------
 
    ENT1 TAB4_X TAB5_D= SIMPLEX TAB1_F TAB2_I TAB3_E (FLOT1);

    Description :
    -------------
 
    The SIMPLEX operator searches for the maximum of a linear
    or linearized function F(Xi) such as :
 
    F(Xi) = F0 + Fi * Xi ;
 
    which is subjected to the following stresses :

    - Xi >EG 0.            primary restraints
    
    - Iji * Xi <EG Ij      restraints of inequality type

    - Eji * Xi  =  Ej      restraints of equality type

    If there is a non-infinite solution, we shall specify :

    - Xi values and the corresponding value of F

    - the distances Dj at the inequalities

    Contents :
    ----------
 
    TAB1_F : table (TABLE type) containing :
             - in TAB1_F.0 : the value    F0   (FLOTTANT)
             - in TAB1_F.i : the values   Fi   (FLOTTANT)

    TAB2_I : table (TABLE type) describing the inequalities
             - in TAB2_I.j.0 : the value  Ij   (FLOTTANT)
             - in TAB2_I.j.i : the values Iji  (FLOTTANT)

    TAB2_E : table (TABLE type) describing the equalities
             - in TAB2_E.j.0 : the value  Ej   (FLOTTANT)
             - in TAB2_E.j.i : the values Eji  (FLOTTANT)

    FLOT1  : optional FLOTTANT qualifying the solution 
             convergence (by default 1.D-10)

    ENT1   : information on the solution
             - ENT1 = 0 there is a non-infinite solution 
             - ENT1 = 1 infinite solution 
             - ENT1 =-1 no possible solution 
 
    TAB4_X : table (TABLE type) containing the primary results :
             - in TAB1_X.0 : the value of F    (FLOTTANT)
             - in TAB1_X.i : the values of Xi  (FLOTTANT)
 
    TAB5_D : table (TABLE type) containing the distances at the
             inequalities :
             - in TAB5_D.i : the values Di   (FLOTTANT)
 
    Notes :
    ---------

    The number of independant inequalities must be strictly smaller
    than the number of unknowns.

    Whether on input or on output, the table indices corresponding 
    to null values can be omitted.

    Even if there are no inequality or (exclusive) equality type
    additional stresses, an empty table will be input.

    If ENT1 is not null, the tables TAB4_X TAB5_D will be empty.