Monthly Archives: November 2011

XY-Chains


This post explains the XY-chain, the most specific, easy to spot, and prolific of Alternating Inference Chains. It includes what many call the XY wing, as the shortest possible XY-chain. One XY-chain can generate multiple toxic candidate pairs. An XY-chain … Continue reading

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Death Blossom Lite


This post describes and illustrates the Death Blossom with bv petals. It is most easily found as a secondary target while looking for XYZ-wings. Death Blossom Lite is a close, and easier to meet, cousin of the WXYZ-wing. First let’s … Continue reading

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ER Winks, Forcing Chains and Irregular XYZ-wings


This post introduces “Empty Rectangle” weak links (ER winks) as a form of “seeing”. It is shown how the ER can be extended by a more general form, the forcing chain. It is also demonstrated that XYZ wings can be … Continue reading

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Regular XYZ-wings


This post explains how the regular XYZ-wing and WXYZ-wing make eliminations with toxic sets. Regular XYZ-wings are illustrated, and the XYZ form of the bv map is introduced. If you are following the Order of Battle, you should be returning … Continue reading

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Introducing Advanced Solving Posts


My next series of posts describe and illustrate well known solving methods which I label as advanced, simply because they use the field of candidates discovered by basic solving techniques. These methods organize slinks (strong links) and winks(weak links) in … Continue reading

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Thoughts on Sudoku Basic Solving


This post concludes my series of posts on basic solving, the actions taken to identify all candidates.  As  the October posts have shown, sysudoku basic solving also identifies and marks strong links and locked sets in boxes and lines.  It … Continue reading

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