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Tough Sudoku for 16/May/2010


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Sudoku Solving Techniques

Submitted by: sudoku lover

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With that little bitty growing season you have up there in the frigid north, Bev, flowers have to fully reveal their beauty ... and do it fast!
16/May/10 12:12 AM
1. start 23 UP=32 (tons of locked set eliminations)
2. (7=6)h4-(6=27)hi3 => ~(7)h2 UP=38.
3. (9=8)d6-(8)d1=(8)f2-(8=9)h2 => ~(9)h6 UP=81.
16/May/10 12:29 AM
Bev - what a sunny greeting this morning!
16/May/10 12:40 AM
I wonder if they have cinquefoils in Cinque Terre?
16/May/10 1:28 AM
I'm not sure of the best way to present this, so I'm hoping someone with experience in the broader Sudoku community will comment. It's an example of a situation on which I commented to Neil on the Apr 27 2010 tough. The chain makes use of information from the immediately preceding More...
16/May/10 2:55 AM
Thanks Sotir and Farpointer for the explanation yesterday.

Regards, Alfred.
16/May/10 4:01 AM
rwm: I don't claim to hail from the 'broader Sudoku community' or even to excel at solving Sudoku puzzles. I do have experience in math, physics and computer programming though.
You're hypothesis, if true, would certainly merit use. However, it seems invalid to me.

what you have is:
16/May/10 4:14 AM
perhaps that last statement could be clearer:

False == (a | b) -- c.
when False == (a = True) -- ???c (True or False).
16/May/10 4:42 AM
Similar to Farpointer's:
1. Note pairs 34 at e12;59 at be3;35 at i12.Unique possibilities to 32.
2. Whether g1=6;OR g1=9,g5=6,c5=8,c8=7=f9;e3=6.UP38.
3. Whether d1=8,d6=9=g5;OR f2=8,h2=9;g1=6.UP81.
16/May/10 4:49 AM
Nice flower and interesting converstation.
16/May/10 4:55 AM
I believe rwm will bloom on farpointer explanation. I seem to understand that more the Alfred/soitr/Neil,etcs (sorry if let someone out).
16/May/10 5:33 AM
16/May/10 7:49 AM
36 minutes 28 seconds of my life I'll never get back! Numerous interruptions by my two sons meant I didn't get a good run at this one so it probably took quite a bit longer than it should have.
16/May/10 10:04 AM
16/May/10 12:27 PM
Hi All, I also found somthing similar to farpointer getting to UP=38 (but my one was a colouring of 6 from h4 which led to an exclusion of 6 in h3, giving UP=38. Then a similar chain to rwm's step 2 (but shorter because of the 27 pair in hi3), which led to UP=81.

However, I believe that More...
16/May/10 8:44 PM
Hi All, In my note above, last paragraph, I should have said 'the mathematicians very' instead of 'their very'.
Best regards, Neil
17/May/10 12:13 AM

I've read your remarks here and on the May 17 page and I'm having trouble relating them to what I've tried to show here. I'm sure there are some who would say my usage here is not good style, but the logic is sound. Again, I probably didn't present the idea clearly enough, or More...
20/May/10 3:52 AM
(8)d1 = h1 - (8)h2 =* [(6=7)h4 - (7=*9)h2 - h6 = (9)g5] - (6)g5 = (6-8)c5 = (8)b6

The stuff in brackets is an Almost AIC, but for the (8) at h2. The asterisks denote the tri-value of the cell h2 - one of which must be true.

The idea being that one can use a Chain that is either More...
20/May/10 2:40 PM

10/Sep/10 9:45 PM
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