PlaySudoku.us
Easy · Puzzle #73
6
8
4
5
1
3
9
5
1
8
7
4
2
5
8
6
1
8
5
3
3
6
8
5
9
6
7
9
3
1
4
1
7
4
5
2
3
8
2
6
8
4
1
6
4
1
5
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.