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 logical structures which confirm candidates as true or false. True candidates are new clues, and false candidates are removed.
The posts explain and illustrate why these structures work, how to find or construct them, and when. The laptop tools of the Solving Tools page help sysudokies do this exactly as illustrated in blog diagrams. However, an inconvenient truth is that the posts no longer introduce the methods in the order recommended in the Sysudoku Order of Battle!
That’s inconvenient, because the posts as first published have you load up several carts before I bring a horse around. But don’t fret, there’s a work-around. Instead of reading the posts by date, you can follow the SSOB. In my updates of these posts, I’m taking that into account. If you are skimming for ideas and not deeply involved, you needn’t bother, but . . .
To follow the Order of Battle, skip now to
Post 20 of 12/22/11 De Coq on Sue de Coq,
Post 21 of 12/27/11 Sysudoku Sue de Coq Verification, then
Post 22 of 1/03/12 Aligned Pair Exclusion
in that order, then hop back to
the next post of 11/10/11, The BV Map and XYZ-wings, and continue by date.
This happened because I changed my mind. Getting into the heart of Sue de Coq, I discovered it was OK to put it first in the bv scan. The APE goes with it. The advantage of having it first is that SdC uses the grid as it is, without transfer of information to another format.
But the next steps in the BV Scan, XYZ-wings and XY chains, are much more easily accomplished by visually endowed but digitally challenged human computers, with a bv map. But Sue de Coq and APE can be devastating. You might not need the map.