PlaySudoku.us
Easy · Puzzle #712
7
5
2
6
1
3
8
2
5
1
6
7
4
9
9
1
2
8
5
1
4
2
9
4
2
5
6
7
4
7
5
2
9
7
6
1
7
8
2
5
4
9
6
1
8
5
7
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.