PlaySudoku.us
Easy · Puzzle #613
8
2
4
9
4
5
7
8
6
6
9
4
1
7
5
9
6
1
2
4
7
7
1
3
9
8
2
3
5
1
9
4
7
2
5
1
2
5
9
5
8
3
1
4
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.