Tag Archives: 2-D trace

A Tracing Exercise with Wex 434


A careful marking session finishes Wex 434 in box marking! This surprising event demonstrates how 2-D depth first tracing fully exploits removals and confirmations. My first time through to a solution I considered Wex 434 among the most deserving of … Continue reading

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An Update on the Slink Marking Bypass


This first post of 2015 updates sysudokies on the slink marking bypass, a preliminary stage of box marking introduced in late 2014. Experience now warrants that the bypass, as it will now be referred to, be accorded a permanent starting … Continue reading

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Nikoli’s X-treme Sudoku


Here we begin a series of reviews that are a clinic on Sysdudoku basic solving skills. Each collection of the survey will be introduced, with several puzzles checkpointed by 2-D traces. This post introduces the Nikoli Publishing top toughy, the … 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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