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Submitted by: Gath

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Another great picture! He looks great for 88!
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Lovely photo Deb
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One long chain is enough to solve this one:

1) Start 23, Unique Possibilities to (UP) 26.
2) c2=1 == i2=1 -- g3=1 == g5=1 forbids c5=1.
3) b7=1 == c7=1 -- c2=1 == i2=1 -- g3=1 == g5=1 forbids b5=1.
4) g5=1 == g3=1 -- b3=1 == b7=1 -- b7=6 == b8=6 -- b8=5 == a8=5 -- a8=3 == a5=3 -- a5=1 == a6=1 forbids a5=1, g6=1. UP 81.
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Deb, is that your Dad? Looks like lots of love & happiness in that picture.
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Good Maen to all! Nice picture to see!
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Didn't even come close to solving this one...
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30:30 after setup. Hi Deb!
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8:something. Good time for me. I'm feeling so sad about the death of Steve Irwin. Such a loss for his family. I hope they can keep the Australian Zoo going.
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Possible proof of tough sudoku of 09 05 06:

1) Start at 23 filled - the given puzzle. Unique Possibilities to 26 filled. (UP 26).
2a) fc on 1's: a6 == i6 -- i2 == c2 forbids c5, a4=1
2b) Locked 1's at 156 forbids b5=1
2c) a5=3 == a8=3 -- a8=5 == b8=5 -- b8=6 == b7=6-- b7=1 == b3=1 -- h3=1 == h5=1 forbids a5=1 UP 81
Sets: 8, max depth 5, rating: .35
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Guess I have a dyslexic proof up there:
1) Start at 23 filled - the given puzzle. Unique Possibilities to 26 filled. (UP 26).
2a) fc on 1's: a6 == i6 -- i2 == c2 forbids c5, a4=1
2b) Locked 1's at 156 forbids b5=1
2c) a5=3 == a8=3 -- a8=5 == b8=5 -- b8=6 == b7=6-- b7=1 == b3=1 -- g3=1 More...
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Chunk proof:

1) Start at 23 filled - the given puzzle. Unique Possibilities to 26 filled. (UP 26).
2a) X wing on 1's at bg35 == b7=1 -- b7=6 == b8=6 -- b8=5 == a8=5 -- a8=3 == a5=3 forbids a5=1
2b) fc on 1's: a6 == a3 -- g3 == g5 forbids bc5=1, i6=1 UP 81
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with 2 guesses
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Is the chunk proof easier? I would previously have assessed it not so, but perhaps it is easier to see. Comments are appreciated!
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I guess if the puzzle is attacked in a logical order, then one would execute the fc on 1's first. Then, paradoxically, if one does not, in my proof, take the locked 1's elimination, then the conditional xwing is there. Of course it is there even after removing the 1 at b5, but it is harder to More...
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Took me an hour to solve.
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No, my Dad passed away in 2002. Alec is an ex neighbour and very good friend. He recently bought himself a computer and has been learning to use it and he's been doing very well with it. He is a fountain of knowledge and has lived through some horrendous times (hiroshima etc). Such a lovely man.
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Good for Alec...he is a smoothie!
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BTW - I have also updated the proof of the previous 2/20/06 monster with a 'chunking' proof that shows that allowing the idea of 'chunking' has some merit. Thus, in my opinion, 'chunking' is probably a valid idea to reduce fc length, and valid also in reducing proof ratings.

This is More...
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I got
proof of 9/4/06 tough:
1) Start with 23
2) UP 26
3) Locked: ghi9=5 => ~bc9=5
4) FC: a6=1 == i6=1 -- g5=1 == g3=1 => ~a3=1
5) Locked: a654=1 => ~bc5=1
6) FC: a6=1 == i6=1 -- i2=1 == c2=1 -- c7=1 == (bc9, c7)=234 -- a8=3 == a5=3
=> ~a5=1
7) UP 81
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to Steve:
I was just airing a few ideas. 'chunking' is not new and applies to many areas, most notably learning and education. An engineer, physicist, programmer etc. would be hopelessly lost in a morass of detail without chunking.
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Hi Pat!
Very nice fc length 4 proof. How would one compare the one you have shown, with the Almost triplet to the one I have shown, with the Almost X wing? One could write a combination:
AFter using the locked 5's:
Xwing on 1's at bg35 == b7=1 -- c7=1 == triplet 234 at c7,bc9 -- a8=3 == a5=3 forbids a5=1.
Is this then length 3, I wonder?
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Hi Pat again!
Well you bring up a great point. If we have learned things about solving puzzles, we ought to be able to use that learned information without suffering some sort of penalty. I certainly appreciate you bringing up the point, and, as I have noted, it certainly has merit.
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how would I rate the difficulty on this one?
a)step 4 isn't really a chain but multi-coloring,
and I can see the elimination on direct inspection - no chain (just for the proof) so that is a multi-color chunk step.
b) the loop on 1's to c7=1 is obvious. the triple with a singleton extra More...
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to Steve:
I think we agree on the point that using 'hard' chunks in chains (especially if required) indicates greater solving difficulty. a physicist can describe heat diffusion very compactly and elegantly with a simple partial differential equation. Someone with only high school algebra, however, is deaf and blind to that beauty.
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although I can work through Clark's proof (thx clark0 and sometimes (?) Steve's, they get complicated for me. So if youre like me it is easier to just look at possibilities like i6 = 1 or 5. It is fairly easy to work out i6 cannot = 1 (simple chain that does not allow either a5 or a8 =3), therefore More...
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It's a bit like a foreign language here.I suppose that that is one of the reasons why the language has developed. Not to inform, but to encode to keep the secret. I like it!
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Hi Ding! (and others who prolly think along the same lines)
Special language is common to many endeavors. The idea is not to obfuscate, but rather to make things more transparent. Unfortunately, without knowledge of the language, it produces the opposite effect.
I read proofs at this More...
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It is nice to see happy people.
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Pretty sad that the US was attacked by Japan and all these years later people want to reference the horror of Pearl Harbor in this way:
'has lived through some horrendous times (hiroshima etc).' Selective memory and/or revisionist history??
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15:41.
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To Patriot.....I am at a loss to know what you are talking about. Yes, I think Hiroshima was horrendous. My reference to it though was merely trying to convey that Alec has lived overseas and been involved in wars and lived a very interesting life. Some of the times in his life have been horrendous. He is a very interesting man to sit and listen to.
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no timer today too..but not more than a good 20 minutes..lovely puzzle and i enjoyed doing it..finished w/o any hiccups smoothly to see this alec of deb who is also a smoothie!!nice pic deb..
cheers
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Nov. 23, 2007.
24/Nov/07 1:04 PM
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SE=7.3
05/Sep/10 9:56 PM
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