PlaySudoku.us
Expert · Puzzle #389
5
2
6
7
6
3
4
1
9
1
1
3
4
7
2
1
5
8
2
9
3
5
9
4
3
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.
"The wisest mind has something yet to learn." — George Santayana
"The wisest mind has something yet to learn." — George Santayana