d/or NF01BB; this value cannot be returned
                without changing the FCN routine(s);
                otherwise, IWARN has the value k*100 + j*10 + i,
                where k is defined below, i refers to the whole
                optimization process, and j refers to the
                initialization step (j = 0, if INIT = 'L' or 'N'),
                and the possible values for i and j have the
                following meaning (where TOL* denotes TOL1 or TOL2,
                and similarly for