Normal Sudoku rules apply. Disjoint Set rules apply.
159 rules apply in the highlighted cells only.
Digits in cages sum to the number in the top left corner.
Xs join cells that sum to 10. Not all Xs are necessarily given.
Solution code: row 9, column 7
on 30. December 2022, 14:44 by AParliamentofOwls
CTC link added
on 23. December 2022, 16:37 by Mr.CHEN
Request to add CTC link