Cross-Line Consistency
This row or column has only a few arrangements left that match its clue — any one that leaves some other row or column with no way to finish is out, and a height used by none of the survivors can be struck.
How it works
- 1The 2 on the left of the second row means only two buildings show along it — the 4 at the edge, then something taller hiding the rest.
- 2Three fillings of that row still match: 4-2-3-5-1, 4-5-3-1-2, and 4-5-3-2-1. Its own clue can't separate them, so Line Consistency stops here.
- 3Try the last one. It puts a 5 in the second column and a 1 in the last, which leaves the bottom row only a 4 for both of those columns — and one row can't hold two 4s.
- 4So that filling is impossible. It was the only one putting a 2 in the fourth cell, so strike the 2 there.
- Height ruled out
- Relationship — The arrow shows which cells support the deduction.