Disjoint RACECAR Quartet
- Palindromes
- Quadruples
- Negative constraint
- Odd and even cells
- Kropki dots
The brief
- Normal Sudoku rules apply.
- Disjoint Set: Digits must not repeat at corresponding box positions.
- A black dot between cells indicates cell values with a 2:1 ratio. ALL BLACK DOTS ARE SHOWN
- Digits along a grey palindrome line read the same forwards or backwards.
- Digits in a white circle must appear at least once in the four surrounding cells.
- Cells with a filled circle must be odd.