Another payoff for expansion of a limited coloring network via AIC slink. It’s an extreme tactic that, after six years of blogging, I finally blundered my way into. This collection illustrates the not-both trial thoroughly.
Please comment if you know of anyone else that has introduced it.
My 132 basic trace:
And here is the line marked grid , fill strings attached:
Maybe these Sudoku are not as hard as I think. What can you find?
My bv scan came up with a regular 475-wing, for one more bv cell. No XY trains running on the railroad.
My constructive inclinations now call for the crayons. Coloring produces an isolated cluster.
An AIC slink extension of blue/green looks like a promising break out.
Testing the not-both is arduous, but 9r1c3 and 7r1c8 are finally proved guilty of something, in this case, a conspiracy to force two 5’s in r6.
Yes, it’s a trial. Trials justify the Sysudoku “extreme” label. You can demote the puzzle by finding a combination of advanced moves that win the solution without a trial.
With its not-both papers signed, 132 traps an interfering 4, allowing a long XY chain to make an indecisive removal.
In the clutter of AIC hinges and chains, there is an ANL, but it only gains two clues.
I post all removals to the X-panel when the action stalls, repeating the scan for chains, fish and pattern restrictions.
This time, a simplified 7-panel revealed a single freeform descending from the now blue 7r1c4. Here, note the failure of an alternative path (red) to reach r5. So either the green army or the blue 7-pattern, is true. To test the latter, we add the blue candidates in the blue/green cluster to the freeform candidates.
And this time, the test is easy. The 6 marks are removed from r8 and c8 by 6r7c2 and 7r8c8.
Marking continues with green candidates, plus the blue freeform candidates not seeing a green candidate. These candidates are eligible to be in a green pattern.
In this case, the collapse of Only Extreme 132 is immediate, and we can continue next post with Only Extreme 175