PlaySudoku.us
Easy · Puzzle #433
9
5
8
1
7
6
4
2
3
7
1
1
2
5
9
3
6
9
5
8
3
7
5
4
2
1
8
8
3
1
4
2
6
8
1
3
6
4
2
3
9
5
3
9
5
4
2
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.