EXi be the number of examples in group i. Currently,
          NEX1 = 6, NEX2 = 9, NEX3 = 2, NEX4 = 4.
          1 &lt;= NR(1) &lt;= 4;
          1 &lt;= NR(2) &lt;= NEXi , where i = NR(1).

  DPAR    (input/output) DOUBLE PRECISION array, dimension (7)
          Double precision parameter vector. For explanation of the
          parameters see [1].
          DPAR(1)           : defines the parameters
                              'delta' for NR(1) = 3,
                              'q' for NR(1).NR(2) = 4.