Syntaxe
=======

.. code-block:: text

    cham_elem = CALC_CHAM_ELEM(
        ◆ MODELE = modele,
        ◇ / TOUT = "OUI" (ou non renseigné),
          / GROUP_MA = grma,
        ◇ INST = float,
        ◇ MODE_FOURIER = int,
        ◆ OPTION = / "FLUX_ELGA",
                   / "FLUX_ELNO",
                   / "PRAC_ELNO",
                   / "COOR_ELGA",
                   / "ROCH_ELNO",
        # Si: equal_to("OPTION", 'ROCH_ELNO')
            ◆ CHAM_MATER = cham_mater,
            ◆ CARA_ELEM = cara_elem,
        # Si: not equal_to("OPTION", 'ROCH_ELNO')
            ◇ CARA_ELEM = cara_elem,
        # Si: is_in("OPTION", ('FLUX_ELNO','FLUX_ELGA',))
            ◆ TEMP = cham_no,
            ◆ CHAM_MATER = cham_mater,
        # Si: is_in("OPTION", ('PRAC_ELNO',))
            ◆ PRES = cham_no,
    )
    
    ◆ : obligatoire
    ◇ : optionnel
    ⟐ : présent par défaut
    & : ensemble
    / : un seul parmi
    | : plusieurs choix possibles