PlaySudoku.us
Expert · Puzzle #851
3
4
6
8
5
9
4
2
5
6
7
1
8
4
4
1
9
9
5
6
1
2
6
Techniques used
- Hidden Single
- Naked Pair
- Naked Single
- Naked Triple
- Pointing Triple
- Box-Line Reduction
- Skyscraper
- XY-Chain
- XY-Wing
"What one man calls God, another calls the laws of physics." — Nikola Tesla
"What one man calls God, another calls the laws of physics." — Nikola Tesla
Set theory provides the formal foundation for Sudoku's rules: each digit must appear exactly once per set.
Set theory provides the formal foundation for Sudoku's rules: each digit must appear exactly once per set.