PlaySudoku.us
Easy · Puzzle #136
8
4
1
6
3
5
8
1
9
2
6
8
7
5
6
7
2
1
8
3
5
9
3
5
6
7
8
5
8
2
7
4
1
6
1
4
3
6
1
5
9
7
7
2
3
4
5
1
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 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.