This post reports on the introduction of pattern slicing, a.k.a. the pink olive, in KD Insane v4, b2, n5 of 7/30/13. The method is defined, and demonstrated on the 3-panel of Insane 425.

Independently of the boomerangs of  the last post, pink olive pattern analysis offers to merge two limited coloring clusters with a common value 3.  Each of the three 3-patterns depends on a pair of colors, but all pairs are consistent with blue and/or orange as true colors, and no freeforms are rejected.

The stage is set for pattern slicing, and going beyond the challenged merger, a pink/olive analysis isolates the true 3-pattern to collapse the puzzle.          

In pattern slicing, we divide the South to  North Freeforms into two sets marked by colors pink and olive. First, we mark the pink and olive collectors, the cells that can only be crossed by freeforms of one color, extending from the starting rows r6 and r4. Cell r1c7 is an olive collector because r4c2 is one and makes r1c2 one.

There are two pink and one olive crossing the collectors, but the dashed pink mixes colors, and can’t be the true pattern.

When it is removed, 3r2c5 and 3r3c2 are orphaned, and N3 is confirmed. The remaining two freeforms are strongly linked. On each line, two candidates are color linked. They can be given regular cluster colors and be part of a coloring cluster. We call it a pattern slink, because one of the 3 patterns is true, and all candidates of the other are false.

In this case, lite coloring was applied to expand the cluster and eventually wrapped the pink candidates for a solution, using several traps unique to lite coloring.  This is reported on the Guide’s lite coloring page Advanced Sysudoku/Lite Coloring.

Next post updates KrazyDad Insane review puzzles 435 and 445.