DATE     95/09/27
    Opérateur APPUI
    ---------------

   RIG1 = APPUI | ('DEPL') ('ROTA') | ('DIRECTION' VEC1) |  FLOT1 GEO1 ;
                |  'RADIAL'  POIN1  POIN2                |
                |   MOT1 ...                             |

    Description :
    _____________

    The APPUI operator constructs the stiffness RIG2, associated
 with linear supports (springs) applied to degrees of freedom.
 Later on, this stiffness will be added to that of the structure.

    Contents :
    __________


    'DEPL'      : key word for putting a support on each of the
                  displacement components

    'ROTA'      : key word for putting a support on each of the
                  rotation components

    'RADIAL'    : key word for restraining the radial displacement  
                  with respect to | the POIN1 point in 2D (POINT
                                  | type)
                                  | the axis POIN1 POIN2 in 3D 
                                  | (POINT type)

    'DIRECTION' : key word for restraining the displacement
                  (by default) or the rotation (key word 'ROTA')
                  according to the direction defined by the VEC1
                  vector

    VEC1        : vector (POINT type)

    MOT1        : one or several names (MOT type) representing the
                  degrees of freedom on which a support is requested
                  (in that case, do not use the aforementioned key 
                  words)

        The possible names for the degrees of freedom are :

  for a computation in MODE PLAN CONT :  UX 
  for a computation in MODE PLAN DEFO :  UX   UY
  for a computation in MODE AXIS      :  UR   UZ   RT
  for a computation in MODE FOUR      :  UR   UZ   UT   RT
  for a computation in MODE TRID      :  UX   UY   UZ   RX   RY   RZ


    FLOT1       : support elastic stiffness (FLOTTANT type)

    GEO1        : object on which the supports will be imposed
                  (MAILLAGE or POINT type)

    RIG1        : generated matrix (RIGIDITE type, RIGIDITE subtype)