Syntax
=====

.. code-block:: text

    interspectrum = DEFI_INTE_SPEC (
        ◇ DIMENSION = int (default: 1),
        ◆/PAR_FONCTION = _F (
               ◆/NOEUD_I = no,
                 /NUME_ORDRE_I = int,
               # If: exists (" NUME_ORDRE_I ")
                   ◆ NUME_ORDRE_J = int,
               # If: exists (" NOEUD_I ")
                   ◆ NOEUD_J = no,
                   ◆ NOM_CMP_I = text,
                   ◆ NOM_CMP_J = text,
               ◆ FONCTION = function_c/function,
            ),
          /KANAI_TAJIMI = _F (
               ◆/NUME_ORDRE_I = int,
                 /NOEUD_I = no,
               # If: exists (" NUME_ORDRE_I ")
                   ◆ NUME_ORDRE_J = int,
               # If: exists (" NOEUD_I ")
                   ◆ NOEUD_J = no,
                   ◆ NOM_CMP_I = text,
                   ◆ NOM_CMP_J = text,
               ◇ FREQ_MIN = float,
               ◇ FREQ_MAX = float (default: 100.0),
               ◇ PAS = float (default: 1.0),
               ◇ AMOR_REDUIT = float (default: 0.6),
               ◇ FREQ_MOY = float (default: 5.0),
               ◇/VALE_R = float,
                 /VALE_C = complex,
               ◇ INTERPOL =/"LIN" (by default),
                            /"LOG ",
               ◇ PROL_DROITE =/"CONSTANT ",
                               /"LINEAIRE ",
                               /"EXCLU" (by default),
               ◇ PROL_GAUCHE =/"CONSTANT ",
                               /"LINEAIRE ",
                               /"EXCLU" (by default),
            ),
          /CONSTANT = _F (
               ◆/NUME_ORDRE_I = int,
                 /NOEUD_I = no,
               # If: exists (" NUME_ORDRE_I ")
                   ◆ NUME_ORDRE_J = int,
               # If: exists (" NOEUD_I ")
                   ◆ NOEUD_J = no,
                   ◆ NOM_CMP_I = text,
                   ◆ NOM_CMP_J = text,
               ◇ FREQ_MIN = float,
               ◇ FREQ_MAX = float (default: 100.0),
               ◇ PAS = float (default: 1.0),
               ◇/VALE_R = float,
                 /VALE_C = complex,
               ◇ INTERPOL =/"LIN" (by default),
                            /"LOG ",
               ◇ PROL_DROITE =/"CONSTANT ",
                               /"LINEAIRE ",
                               /"EXCLU" (by default),
               ◇ PROL_GAUCHE =/"CONSTANT ",
                               /"LINEAIRE ",
                               /"EXCLU" (by default),
            ),
        ◇ TITRE = text,
        ◇ INFO =/1 (by default),
                 /2,
    )
    
    ◆: mandatory
    ◇: optional
    : present by default
    &: together
    /: only one among
    |: several possible choices