Sue de Coq
Extreme
Reference only
An advanced intersection technique that combines naked and hidden subsets across a box and one of its lines at the same time.
The solver does not attempt this technique, so Smart Hint will never suggest it. It is documented because you may still want to spot it yourself.
- Cells that establish the pattern
- Where the conclusion lands
- Candidate ruled out
How it works
- A1 and B1 sit in both this box and row 1 — the intersection — and together hold exactly {1, 2, 3} across two cells: an Almost Locked Set.
- Splitting {1, 2, 3} between a box-only digit (2, tied up elsewhere in the box) and a row-only digit (1) lets each be eliminated from the rest of its own unit — 1 from E1 in the row, 2 from C3 in the box — without ever pinning down which intersection cell holds which digit.