Tag Archives: ALS

Harvest from the Assistant Report

Posted on September 2, 2014 by Sudent

This post summarizes what led to the review of Bob Hanson’s web report on his Sudoku Assistant, and what was gained from it. There is also an instructive checkpoint on a T&E method endorsed in the report. I’ve been on … Continue reading →

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Sudoku Assistant’s ALS Toxic Sets

Posted on July 22, 2014 by Sudent

This post reviews Bob Hanson’s illustrations on ALS toxic sets, in Sudoku Assistant – Solving Techniques. For these illustrations, Hanson uses the bent naked n-set examples of the previous post. Strangely enough, this extreme economy brings insights. Bob Hanson designed … Continue reading →

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Absolutely Nasty 4 Review Snaps I

Posted on March 5, 2013 by Sudent

Here we link back to advanced solving posts as we enjoy sysudokie solving snapshots from the review table puzzles 0f Frank Longo’s Absoutely Nasty Level 4 (AN4) collection.  Did you ever get trapped looking at a neighbor’s vacation slides ?  You … Continue reading →

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ALS Merged Cell Forcing Chains

Posted on December 4, 2012 by Sudent

This post demonstrates the merger of cell forcing chains by means of ALS nodes.  I  checkpoint  three triple cell forcing chains from the challenge of the previous post, and argue that comprehensive search for cell forcing chains beyond the dual level … Continue reading →

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Cell Forcing Chains

Posted on November 27, 2012 by Sudent

Here we examine forcing chains starting from all candidates in a cell.  When the number of chains is 2, there is nothing new.  Above that,  there is a new strategy to explore, which rivals LPO in complexity, but falls behind … Continue reading →

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Enumerating the ALS-XZ

Posted on July 24, 2012 by Sudent

This post was revised in October 2015 to update the enumeration method for ALS  toxic pairs demonstrated in the previous post. Here I also checkpoint the basic solving of demonstration puzzle of Sudoku Maestro 8-9, Fall 2009. In the next, … Continue reading →

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ALS Toxic Sets

Posted on July 17, 2012 by Sudent

A pair of non intersecting almost locked sets can define a toxic set. This kind of removal may be discovered at any time, but I place closure on ALS generated toxic sets very late in the Systematic Sudoku Order of … Continue reading →

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