Normal sudoku rules apply. Place 9 ‘halvers’ (one in each row, column and 3x3box) into the grid. Each digit must appear in a halver cell. The value of a halver is half its digit. The 3x3 box borders divide each blue line into segments and the sum of the values on each segment must be the same. (Different lines may have different segment sums). The shaded dominoes are clones: ie they contain the same digits in the same positions. Eg if r2c3 is a 1 then r5c7 is a 1 and r9c4 is a 1.