Logic Masters Deutschland e.V.

This here is what can happen if you marry disjoint groups with a 159-type constraint (but using columns 2+5+8 instead).

• Normal sudoku rules apply: Each row, column, and region indicated by thick borders in the grid must contain the digits 1 to 9 once each.
• Disjoint groups: Digits cannot appear in the same relative position within different box regions. (E.g. r1c1 and r4c4 cannot contain the same digit.)
• 258: Digits in column 2 indicate the column in which the digit 2 appears in that row (e.g. if r3c2 is a 6, r3c6 is a 2). The same is true of column 5 and the digit 5, and column 8 and the digit 8.
• The inequality sign between r4c7 and r4c8 points towards the smaller digit.

You can play this puzzle online using:

• CTC app: https://tinyurl.com/s25w2unr
• f-puzzles: https://f-puzzles.com/?id=yffwxtnw

Good luck!