PlaySudoku.us
Evil · Puzzle #440
5
6
4
3
5
2
6
9
1
2
8
1
4
4
5
2
3
1
4
2
6
9
6
7
7
9
"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.