Unique Rectangle 2D
Unique Rectangle 2D: Because the puzzle has exactly one solution, any pattern that would give two can be ruled out.
How it works on this board
Following the ALS-XZ constraint, assuming the target makes the pattern swappable
3
1
2
9
6
4
1
2
8
1
8
1
2
9
9
8
3
2
7
8
4
1
6
9
2
1
9
5
2
6
2
4
1
9
No marks yetPosition 0 / 2