PlaySudoku.us
Easy · Puzzle #154
7
1
3
6
4
9
3
5
2
4
1
8
5
8
7
6
1
2
3
1
8
2
3
6
2
9
5
7
3
1
7
6
1
5
3
8
6
6
2
1
3
5
3
4
6
1
7
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.