GridDay

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Inequality Chain

Intermediate Places a digit Used in: Futoshiki

Inequality Chain

Follow the greater-than and less-than signs linking a run of cells. Each sign caps how high or low a value can be; a long enough chain of “<” signs on a small grid pins exact values — four cells reading a < b < c < d on a 4×4 must be 1, 2, 3, 4.

How to spot it

A run of cells connected by greater-than and less-than signs.

What you can conclude

Each sign trims a cell’s range; a long enough chain fixes exact values.

Worked example

Four cells reading a < b < c < d on a 4×4 can only be 1, 2, 3 and 4 in order.