Use inequalities in Futoshiki
A Futoshiki grid combines row and column uniqueness with less-than relationships. Each type of clue can remove possibilities that the other leaves open.
By Zehano · Original AI-assisted explanation and worked example · Updated 16 October 2026 · Editorial approach
A worked example
In a four-cell row, the available numbers are 1, 2, 3 and 4. If a cell is less than its neighbour, the first cannot be 4 and the second cannot be 1. If another clue fixes the second to 2, the first must be 1. After placing it, remove 1 from other cells in that row and column.
Try it in three steps
- Write the allowed digits for the board size.
- Apply each inequality in the stated direction.
- Recheck row and column uniqueness after a placement.
What to watch for
A less-than sign does not mean the values differ by exactly one. The pair 1 and 4 can satisfy 1 < 4 unless other clues rule it out.
Apply it to your own material
Choose one topic from your current course or project. Write down the question you want to answer, make an attempt, and keep a note of how you checked it. Use the example above as a pattern; replace its subject matter and assumptions rather than copying an answer into a different task.
Open Futoshiki ↗