Diagonal 3-1 Transfer
A corner 3 transfers one required line through a shared dot, using up the diagonal 1's allowance there.
How it works
- 1These two clues never share an edge — only the dot between them — yet that dot's four edges are exactly two sides of each cell, which is enough to check every combination of the pair at once.
- 2The 3 sits in the board's corner, so its two outer sides are already drawn; it needs one more line, and both candidates run into the shared dot.
- 3Whichever it picks, the dot is left needing exactly one more line, and the only edges it has left are the 1's top and right.
- 4So the 1 spends its single line up at that dot: cross off its bottom and its left.
- Edge on the loop
- Edge ruled out
- Cells that establish the pattern