******** fig2.5 **********

        int
        max_subsequence_sum( int a[], unsigned int n )
        {
                int this_sum, max_sum, best_i, best_j, i, j, k;

/*1*/           max_sum=0; best_i= -1; best_j= -1;
/*2*/           for(i=0; i<n; i++ )
/*3*/                   for(j=i; j<n; j++ )
                        {
/*4*/                           this_sum = 0;
/*5*/                           for(k=i; k<=j; k++ )
/*6*/                                   this_sum += a[k];

/*7*/                           if( this_sum > max_sum )
                                {	/* update max_sum, best_i, best_j */
/*8*/                                   max_sum = this_sum;
/*9*/                                   best_i = i;
/*10*/                                  best_j = j;
                                }
                        }
/*11*/          return( max_sum );
        }