Syntax
=====

.. code-block:: text

    /interspectrum
    /tran_gene = DYNA_ISS_VARI (
        ◆/EXCIT_SOL = _F (
               ◆ | ACCE_X = function,
                 | ACCE_Y = function,
                 | ACCE_Z = function,
            ),
          /NB_FREQ = int,
        ◇ PRECISION = float (default: 0.999),
        ◇ ISSF =/"OUI ",
                 /"NON" (by default),
        ◆ INTERF = _F (
             ◆ GROUP_NO_INTERF = grno,
             ◆ MODE_INTERF =/"CORP_RIGI ",
                             /"TOUT ",
                             /"QUELCONQUE ",
          ),
        ◆ MATR_COHE = _F (
             ◆ TYPE =/"MITA_LUCO ",
                      /"ABRAHAMSON ",
                      /"ABRA_ROCHER ",
                      /"ABRA_SOLMOYEN ",
             # If: equal_to (" TYPE ", 'MITA_LUCO')
                 ◆ VITE_ONDE = float,
                 ◇ PARA_ALPHA = float (default: 0.1),
          ),
        ◇ UNITE_RESU_FORC = unit (default: 33),
        ◇ UNITE_RESU_IMPE = unit (default: 32),
        ◇ TYPE =/"BINAIRE ",
                 /"ASCII" (by default),
        ◆ MATR_GENE = _F (
             ◆ MATR_MASS = matr_asse_gene_r,
             ◆ MATR_RIGI = matr_asse_gene_r/matr_asse_gene_c,
             ◇ MATR_AMOR = matr_asse_gene_r/matr_asse_gene_c,
          ),
        ◇ INFO =/1 (by default),
                 /2,
        # If: exists (" EXCIT_SOL ")
            ◇ & FREQ_MAX = float,
              & FREQ_PAS = float,
        # If: exists (" NB_FREQ ")
            ◆ FREQ_INIT = float,
            ◆ FREQ_PAS = float,
            ◇ OPTION =/"TOUT" (by default),
                       /"DIAG ",
            ◆ NOM_CMP =/"DX",
                        /"DY",
                        /"DZ",
    )
    
    ◆: mandatory
    ◇: optional
    : present by default
    &: together
    /: only one among
    |: several possible choices