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Tough Sudoku for 22/May/2010

                 
                 
                 
                 
                 
                 
                 
                 
                 

Choose a number, and place it in the grid above.

  1 2 3 4 5 6 7 8 9
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Submitted by: Gath

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Regardless, Mr. Cornstalk ... we appreciate the valiant effort!
22/May/10 12:12 AM
A persistant strain of corn!
22/May/10 1:08 AM
1) Start 22 UP 27
2a) LC(2)def9 => ghi9<>2
2b) XW(5)eg24 => e15g35<>5
2c) (6)c5= (6-8)a4 = e4 - (8=2)e5 => c5<>2
2d) (6)c5 = (6-8)a4 = (8-5)e4 = g4 - h5 = (5-6)h3 = (6)h5 loops => a4<>29, e4<>2; h3<>238; h5<>23
2e) LC(2)ac6 => efhi6<>2; UP 81

9 unique sis required + UPs
22/May/10 1:27 AM
1. Basic techniques to UP = 27
2. (5): X-wing eg2|eg4 => e15, g35 <> 5
3. (2=798)ac6|b5 - (8=2)e5 - (2=9)d4 - (9=562)gi4|h5 => c5, h6 <> 2 ; UP = 81

Steve: Thanks for the comment on the May 16 page.
22/May/10 1:45 AM
rwm very nice step 3! I would add hi6<>2
22/May/10 1:53 AM
Have a great weekend, everyone!
22/May/10 1:56 AM

1)Start at 22,basic techniques to UP=27
2)Loop:(5)e4=g4-g2=(5-6)e2=i2-i4=(6-8)a4=(8)e4
=>e15g35<>5,e2=56,i13<>6,a4=68 ,e4=58
3)(3)h6=(3-7)i6=g5-(7=8)b5-(8=2)e5-c5=(2)ac6,=>h6<>2.UP=81
22/May/10 2:12 AM
26:39
22/May/10 3:11 AM
maen all! nice drip strip...the week we put our corn in it froze, flooded, and then the wind blew for a week...its ankle high already and doing fine...luckily it was still underground through the bad stuff...we still won't get any sweet until august the earliest.
22/May/10 3:13 AM
a little different twist: at rwm's step 3:
3. (8=279)agi7-(2)h7=(2)h6-(2)a6=(*256)a431, => a431<>8 UP=81.
22/May/10 3:35 AM
rwm: I just read your May-16 note (to see Steve's input). Clearly you misunderstood my note of May-17. That was a reversal of my May-16 first impression and an affirmation of the idea (with the reservations about where deductions are pulled when using what I now call K-Sets.).
22/May/10 4:27 AM
1. Unique possibilities to 27.
2. If a4=8=c7,b5=7,(pair 29 at ac6),h6=3,h8=1;column c is devoid of 1.So e4=8.UP81.
22/May/10 7:06 AM
35:26, too long but at least I finished it. all.
22/May/10 7:17 AM
Alfred - a very nice step you found. I especially like that you can execute your step without using any other techniques except singles before and after. Congrats on reducing this puzzle to a one trick pony! I know that you do not prefer AIC's or other terminology. I hope that you are not More...
22/May/10 9:15 AM
There's always next season!!
22/May/10 9:29 AM
Thanks Steve.You are welcome to "translate" my step to Eureka notation. Because I am not so familiar with that notation, to me, it looks much more complicated.

Regards, Alfred.
22/May/10 9:48 AM
one trick? you still have to make hidden and locked set eliminations after (8)e4 to get UP 81.
The chain I used doesn't require the (5)XWing step and proves (8)e4 inter alia. (uses 3 strong sets). So:

1. basic techniques UP=27.
2. (8=279)agi7-(2)h7=(2)h6-(2)a6=(*256)a431, => ~(8)a431 UP=81.
22/May/10 10:29 AM
Hi farpointer. After e4=8,g4=5=h3,all the rest seem to be UPs.

Regards, Alfred.
22/May/10 11:24 AM
Alfred: that wasn't my point. Are you (and Steve) really claiming - hmm.. I see this naked triple sitting here .. oh well, I will just ignore it and look for some complicated ten link chain leading to a contradiction instead! - I don't buy it.
22/May/10 2:07 PM
farpointer: To go from the original puzzle (UP22) to UP27, every new cell has only one possibility. Any other possibilities lead to an immediate contradiction. After e4=8, the same applies from UP27 to UP81. I have just checked on that again.
There is a 56 pair at h35 in this puzzle, but it did not have to be invoked here.
Regards, Alfred.
22/May/10 4:30 PM
Farpointer,
I merely wished to comment that Alred's step did not require any of the simple steps except singles to execute, and that it did not require any steps but singles after execution.
I would think that it is rare that one would not execute, or at least note, the simple steps that More...
22/May/10 6:53 PM
21:39
22/May/10 11:11 PM
25:23 in order
26/May/10 2:15 AM

SE=7.2
10/Sep/10 9:47 PM
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