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SOLO-019 · Futoshiki

EXTREME

The Eight Passages

Complete square 8 × 8 with figures from 1 to 8.

Materials: Pencil, gum and gridded paper; no commercial game required.

Rules you need

The puzzle

All useful inequalities are given below; the neighbourhoods not mentioned do not bear any additional constraints.

L4C1 < L4C2

L5C6 < L5C7

L8C2 < L7C2

L1C5 < L1C4

L6C2 < L6C3

L1C2 < L2C2

L5C1 < L4C1

L4C5 < L3C5

L2C3 < L2C2

L4C3 < L4C2

L6C1 < L6C2

L3C6 < L3C7

L7C3 < L6C3

L6C4 < L5C4

L8C8 < L8C7

L5C2 < L4C2

L4C2 < L3C2

L1C2 < L1C3

L6C1 < L5C1

Coordinates: lines from top to bottom, columns from left to right.
L / C12345678
1·5··27··
2··23····
36·······
4········
5··4···8·
6·····8·1
7···582··
8···63···
Why this level?

The crossover of single lines, single columns and inequities is not closed by propagation of the only forced numbers in the reference solver. Entwined hypotheses and non-local contradictions are necessary in its method; this motivates the Extreme level, without pretending to exclude a shorter human trick.

Your workspace

Write down your assumptions separately from deductions you have proved.