PlaySudoku.us
Evil · Puzzle #556
3
7
4
9
4
2
1
6
9
5
7
4
1
1
3
2
6
7
8
1
9
6
7
5
4
2
"No amount of experimentation can ever prove me right; a single experiment can prove me wrong." — Albert Einstein
"No amount of experimentation can ever prove me right; a single experiment can prove me wrong." — Albert Einstein
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.