All tags/Sudoku
The puzzle
The classic example puzzle, its givens bold and the open cells ready to print.
{sudoku '53..7....6..195....98....6.8...6...34..8.3..17...2...6.6....28....419..5....8..79'}
| 5 | 3 | empty | empty | 7 | empty | empty | empty | empty |
| 6 | empty | empty | 1 | 9 | 5 | empty | empty | empty |
| empty | 9 | 8 | empty | empty | empty | empty | 6 | empty |
| 8 | empty | empty | empty | 6 | empty | empty | empty | 3 |
| 4 | empty | empty | 8 | empty | 3 | empty | empty | 1 |
| 7 | empty | empty | empty | 2 | empty | empty | empty | 6 |
| empty | 6 | empty | empty | empty | empty | 2 | 8 | empty |
| empty | empty | empty | 4 | 1 | 9 | empty | empty | 5 |
| empty | empty | empty | empty | 8 | empty | empty | 7 | 9 |