Tag Archives: remote pair

Logic Justifies Aligned Triple AIC Hinges

Posted on September 25, 2018 by

This post takes on a challenge puzzle 17 which follows the Figure 30.1 of the previous post, in Andrew Stuart’s The Logic of Sudoku.   A boomerang ANL shows why aligned triple candidates are eligible to be AIC hinge partners. Logic … Continue reading →

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Bean’s Extremely Hard I

Posted on July 25, 2017 by

A review of Rebecca Bean’s 600 Extremely Hard Sudoku Puzzles with Answers begins with the review table and two puzzles, 7-6 and 12-6. The collection is mostly basic, with the half of them solved by the slink marking bypass. Puzzle … Continue reading →

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Ardson Very Hard v.2 198 and 238

Posted on May 23, 2017 by

The review of A.D. Ardson Very Hard Puzzles v.2 continues with Ardv2 198 and 238. The sysudokie resolution to 198 is a rerun of 158, but 238 is a classic remote pair example. Ardv2 198 barely escapes the bypass, but … Continue reading →

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THLS Limps In On Chains

Posted on January 24, 2017 by

This post identifies the conjugacy chain, the last fundamental chain type to be introduced in The Hidden Logic of Sudoku, as a weakened X-chain.  Since the last few chapters introduce extensions for XY chains, it becomes clear that THLS is … Continue reading →

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CLEF Homework on Unsolvable 190

Posted on May 3, 2016 by

Here is a checkpoint Sysudoku reader’s homework on the Sysudoku Cross Line Exocet Filter introduced in the previous post. Was it hard?  I stumbled many times on the 3467 case of the last week, and I may need corrections on … Continue reading →

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Hodoku XY-Chains

Posted on October 13, 2015 by

As we explore Hodoku Chains and Loops (tech-chains.php) examples, here I contrast the premise starting, chain following school of Stephens/Hodoku, with the Sysudoku find-em-all technique of XY-rails. Also, a mathematically sensible order is suggested for remote pairs, as a Hodoku … Continue reading →

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Revisiting Wex 435

Posted on July 21, 2015 by

This post updates the Weekly Extreme Review with a revisit of Wex 435, a puzzle that proved resistant to the single alternate Sue de Coq and was deemed the toughest in the review series, inspiring an extreme ALS trial, the … Continue reading →

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