An AIC Checkpoint and Challenge


Here we finish off a puzzle that dazzles with artful AIC.  And I hand out a sysudokie AIC solo challenge.  First comes your checkpoint on the alternative route to the initial AN confirming loop, built upon the luscious 2-chain on the Maestro 47 2-panel.

 

Superimposing the alternating part of this chain on the grid, an almost identical AIC extension completes the AN confirming loop, yielding E3=>(W3m, E7m). 

 

 

 

 

But wait! That may not be the loop you found, but you’re still correct!  There is another slink out point on the 2-chain, and it leads to a third AN loop confirming the same clue!

 

A third solution AN loop is a combination of the first two.  The three AN loops show us how wiggly the AICs  are.  The hinge cells play a similar role in all three of them.

Moving on to the consequences

E3=>(W3m, E7m),

the second AN loop evolves into a new AN loop confirming W2.

 

 

 

The 8 removal creates an 8-ANL confirming SE8.

 

 

 

 

 

The 7 marks in East also permit two grouped AIC.  In red, the bv r5c7 is inverted to act as an AIC hinge. The toxic set has a group member.  In green, links are reversed and bv r6c5 is an AIC hinge. The grouped  toxic set removes  a candidate in the same unit!

 

Following up,  SE8=>(NE8m, SW8t,  NEc9np37=>c9np49) brings more AIC fireworks:

 

Two toxic sets, the lower one in red, a 4-chain; the upper one in purple, and AIC.  In the AIC,  cell r6c6 a bv  is inverted to act as an AIC hinge.

The removal of 1 in r2c7 turns out to be the decisive blow. On the 1-panel:

 

 

 

 

But of course, there’s another way to do it, via AIC.  Maestro 47 collapses, but don’t take my word for it.

As your financial reports always warn, “Past performance is not necessarily indicative of future results”.  Maestro 47 was selected, if not designed, to show off AICs.  It was a doozy!

Now for your AIC solo effort, the checkpoint on sysudokie basic solving of Maestro 49 of the previous post  is

Box marking:

1: Nm=>Sm, Em.  2: NWm=>SWm.  3:  4:  5: SEm.   6: NEm.  7: NEm, Nm, W7=>SWm. 8:  9: Em, SWm.

Line Marking:  5f: r2, r6, c6  6f: r4, c1, c3, c5, c9  7f: c2, c7, c8  8f: c4.  Close: r1, r3, r5, r7, r8, r9.

Now APE r46c7: 13+14+19+39+49 removes 2, due to bv 29 and ALS 2346 in Ec8, and after a 6-chain removal,, you have

 

Put in a blue/green cluster with blue 7 in r2c4.  Mark your AIC hinges, find an AIC extension of the 6-chain, and go as far as you can, for next Tuesday post.  Break a pencil!

 

 

Advertisements

About Sudent

My real name is John Welch. I'm a happily married, retired professor (computer engineering), timeshare traveling, marathon running father of 3 wonderful daughters and granddad to 7 fabulous grandchildren. The blog is about Sudoku solving. It covers how to start, basic solving to find candidates efficiently, and advanced solving methods in an efficient order of battle. It is about human solving methods, not computer solving.
This entry was posted in Advanced Solving and tagged , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s