The case notes
How Nabner lines work
No two digits anywhere on a Nabner line are consecutive or repeated. Watch a worked example, then try the idea in a puzzle.
Put it into practice
No close pairs
A Nabner line has a negative rule. No two digits on it may be consecutive, and none may repeat.
2 bars 1 and 3
Two is on this line. That bars one and three everywhere else on the line, not just in the next cell.
Only 7, 8 or 9
Five bars four and six. Two and five themselves cannot repeat. That leaves seven, eight or nine for the last cell.
The row leaves 7
The ordinary row rule finishes it. Eight and nine are already in this row, so the last line cell must be seven.
2, 5, 7 works
The line now reads two, five, seven. Check every pair: no neighbours in value and no repeats.
Read the transcript
A Nabner line has a negative rule. No two digits on it may be consecutive, and none may repeat. Two is on this line. That bars one and three everywhere else on the line, not just in the next cell. Five bars four and six. Two and five themselves cannot repeat. That leaves seven, eight or nine for the last cell. The ordinary row rule finishes it. Eight and nine are already in this row, so the last line cell must be seven. The line now reads two, five, seven. Check every pair: no neighbours in value and no repeats.
