DATE     94/01/10
    Procédure BOA
    -------------

    TAB1 = BOA  (TAB2) ;

    Description :
    ____________

    The BOA procedure enables the user to mesh pipework lines
 in interactive mode. The supplied data are similar to
 those usually found on a plane.


    Contents :
    __________

    TAB2  : optional operand (TABLE type)
            TAB2 stems from a former execution of BOA.
            TAB2 can thus be completed or corrected.

    TAB1  : generated object (TABLE type)

    Note :
    ________

    TAB1 is split up as follows :

           TAB1 'MAILLAGE' : total mesh

           TAB1 MOT1       : table describing the pipework line 
                             named MOT1

           TAB1 MOT1 'MAILLAGE' : mesh of the line MOT1
           TAB1 MOT1 'TRONCON'  : table of the meshes of a line 
                                  sections
                                  
           TAB1 MOT1 'ELEMENT'  : type of geometrical element for the
                                  line MOT1
           TAB1 MOT1 'PENTE'    : default slope of the line MOT1
           TAB1 MOT1 'ENTREE'   : length unit on input
           TAB1 MOT1 'SORTIE'   : length unit on output
           TAB1 MOT1 'COULEUR'  : color for the line MOT1

    Use :
    _____

    - It consists in answering the questions for describing the
      pipeworks which are defined as adjacent sections.

    - It is possible to define sections of straight line, arcs,
      elbows, and double-elbows with a possible difference in
      level.

    - The "name" of a line or section actually refers to the name
      of the index that locates the object in the appropriate
      table. It is a MOT type object which should be supplied 
      between apostrophes.

    - In case of data error, the BOA procedure may prematurely stop
      and produce a wrong TAB1 object. If this should arise, run
      BOA once again without performing any modification and
      the obtained results could well re-array by themselves.