PlaySudoku.us
Evil · Puzzle #715
8
2
7
5
4
6
4
8
3
8
7
9
4
2
7
9
6
3
8
5
4
7
9
6
1
8
Techniques used
- Naked Single
- Hidden Single
- Naked Pair
- Pointing Pair
- 2-String Kite
- XY-Chain
- XY-Wing
- Naked Triple
- W-Wing
- Simple Coloring
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
"Absorb what is useful, discard what is useless, and add what is specifically your own." — Bruce Lee
"Absorb what is useful, discard what is useless, and add what is specifically your own." — Bruce Lee