Inequality Bound
Across a sign, the smaller cell can't reach the larger cell's biggest candidate, and the larger cell can't drop to the smaller cell's smallest.
How it works
- 1Both signs point left, so the three cells climb: first < second < third.
- 2Take the middle sign first. The third cell can be at most 4, so the second must be at most 3; the first must be at least 1, so the second must be at least 2.
- 3Now feed that back. The second cell tops out at 3, so the first tops out at 2; the second starts at 2, so the third starts at 3.
- 4Read the run as a whole and the same answer falls out in one go: three cells climbing need three different values in order, so the first can only be 1 or 2, the second only 2 or 3, and the third only 3 or 4.
- 5This is the move you will make more than any other. There is no separate “chain” technique to learn — applying this one sign at a time, over and over, gets you exactly the same bounds a whole-chain reading would.
- Candidates this technique rules out
- Smaller → larger — The arrow follows the direction imposed by the inequality sign.
- Cells read together — The connecting line shows which cells combine to make the deduction.
- Conclusion — The coloured candidate, or the final arrow when it lands outside the pattern, shows the result.