Syntax
=====

.. code-block:: text

    IMPR_FONCTION (
        ◇ FORMAT =/"TABLEAU" (by default),
                   /"AGRAF ",
                   /"XMGRACE ",
                   /"LISS_ENVELOP ",
        # If: equal_to (" FORMAT ", 'XMGRACE')
            ◇ PILOTE =/"" (by default),
                       /"POSTSCRIPT ",
                       /"EPS ",
                       /"MIF ",
                       /"SVG ",
                       /"PNM ",
                       /"PNG ",
                       /"JPEG ",
                       /"PDF ",
                       /"INTERACTIF ",
                       /"INTERACTIF_BG ",
            ◇ UNITE = unit (default: 29),
        # If: equal_to (" FORMAT ", 'AGRAF')
            ◇ UNITE = unit (default: 25),
            ◇ UNITE_DIGR = unit (default: 26),
        # If: not equal_to (" FORMAT ", 'LISS_ENVELOP')
            ◆ COURBE = _F (
                 ◆/FONCTION = formula/function_c/function/table cloth,
                   /LIST_RESU = listr8,
                   /FONC_X = formula/function,
                   /ABSCISSE = float,
                 # If: exists (" FONCTION ")
                     ◇ LIST_PARA = listr8,
                 # If: is_type (" FONCTION ") in (function_c, formula_c)
                     ◇ PARTIE =/"REEL ",
                                /"IMAG ",
                 # If: exists (" LIST_RESU ")
                     ◆ LIST_PARA = listr8,
                 # If: exists (" FONC_X ")
                     ◆ FONC_Y = formula/function,
                     ◇ LIST_PARA = listr8,
                 # If: exists (" ABSCISSE ")
                     ◆ ORDONNEE = float,
                 ◇ LEGENDE = text,
                 ◇ STYLE = int,
                 ◇ COULEUR = int,
                 ◇ MARQUEUR = int,
                 ◇ FREQ_MARQUEUR = int,
                 ◇ TRI =/"N" (by default),
                         /"X",
                         /"Y",
                         /"XY",
                         /"YX",
              ),
        # If: equal_to (" FORMAT ", 'LISS_ENVELOP')
            ◆ COURBE = _F (
                 ◆/NAPPE = tablecloth,
                   /NAPPE_LISSEE = tablecloth,
              ),
        # If: equal_to (" FORMAT ", 'TABLEAU')
            ◇ UNITE = unit (default: 8),
            ◇ TITRE = text,
            ◇ SOUS_TITRE = text,
            ◇ SEPARATEUR = text (default: ""),
            ◇ COMMENTAIRE = text (default: "#"),
            ◇ COMM_PARA = text,
            ◇ DEBUT_LIGNE = text,
            ◇ FIN_LIGNE = text (default:"
    "),
            ◇ FORMAT_R = text (default: "E12.5"),
        # If: not equal_to (" FORMAT ", 'TABLEAU')
            ◇ TITRE = text,
            ◇ SOUS_TITRE = text,
            ◇ BORNE_X = float,
            ◇ BORNE_Y = float,
            ◇ ECHELLE_X =/"LIN" (by default),
                          /"LOG ",
            ◇ ECHELLE_Y =/"LIN" (by default),
                          /"LOG ",
            ◇ GRILLE_X = float,
            ◇ GRILLE_Y = float,
            ◇ LEGENDE_X = text,
            ◇ LEGENDE_Y = text,
        # If: equal_to (" FORMAT ", 'LISS_ENVELOP')
            ◇ UNITE = unit (default: 25),
        ◇ INFO =/1 (by default),
                 /2,
    )
    
    ◆: mandatory
    ◇: optional
    : present by default
    &: together
    /: only one among
    |: several possible choices