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Puzzle 10/07/15: XY

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Thu Jul 15, 2010 7:51 am    Post subject: Puzzle 10/07/15: XY Reply with quote

Code:
 +-----------------------+
 | 9 . 3 | 7 . 1 | . 4 . |
 | . . . | . 4 3 | 7 . . |
 | 4 . 6 | . 9 . | 3 1 2 |
 |-------+-------+-------|
 | 8 . . | 3 7 . | . . . |
 | . 3 7 | 4 1 . | . . . |
 | 1 4 . | . . . | . . . |
 |-------+-------+-------|
 | . 9 4 | . . . | 1 5 . |
 | 3 . 5 | . . . | 6 . . |
 | . . 1 | . . . | . . 3 |
 +-----------------------+

Play this puzzle online at the Daily Sudoku site

Code:
 after basics
 +-----------------------------------------------------------------------+
 |  9      25     3      |  7      26     1      |  8      4      56     |
 |  25     1      8      |  26     4      3      |  7      69     569    |
 |  4      7      6      |  58     9      58     |  3      1      2      |
 |-----------------------+-----------------------+-----------------------|
 |  8      56     29     |  3      7      259    |  4      269    1      |
 |  56     3      7      |  4      1      259    |  259    8      69     |
 |  1      4      29     |  589    2568   25689  |  259    3      7      |
 |-----------------------+-----------------------+-----------------------|
 |  267    9      4      |  26     3      267    |  1      5      8      |
 |  3      28     5      |  1      28     79     |  6      79     4      |
 |  67     68     1      |  589    568    4      |  29     279    3      |
 +-----------------------------------------------------------------------+
 # 52 eliminations remain
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Thu Jul 15, 2010 8:22 pm    Post subject: Reply with quote

First pass was a five stepper.........

Quote:
Type 4 UR58 r36c46; r6c4<>5

Found contradiction chain searching for extended xy-wing: (9)r9c3-(9=2)r4c3-r4c8=r9c8-(2=9)r9c7-r9c4=(9)r6c4; r6c3<>9

AXY-wing 2-68 vertex (2*0r8c5, pincers (26)r7c4 & (68)r6c5 with fin (5)r6c5
If xy-wing is true: r9c5<>6
If fin is true: (5)r6c5-(5=9)r6c7-r9c7=r89c8-(9=6)r2c8-r2c4=(6)r7c4; r9c5<>6

xy-wing -569 with vertex (69)r5c9; r5c7<>5

BUG+2[(9)r9c8=(6)r2c9]-(6=9)r2c8; r8c8<>9


A second pass was a one stepper.......

Quote:
ANP(29=7)r9c78-(7=6)r9c1-(6=5)r5c1-(5=2)r2c1-(2=6)r2c4-(6=9)r2c8-(9=7)r8c8; r9c8<>7

Ted


Last edited by tlanglet on Thu Jul 15, 2010 9:45 pm; edited 1 time in total
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK

PostPosted: Thu Jul 15, 2010 9:41 pm    Post subject: Reply with quote

A wing..
Quote:
w-wing(56) (6=5)r1c9 - r1c2=c2c1 - (5=6)r5c1; r5c9<>6


Back from my hols! Spain was hot 40+ (metric system) and happy to beat the Dutch!
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Mogulmeister



Joined: 03 May 2007
Posts: 1151

PostPosted: Thu Jul 15, 2010 9:50 pm    Post subject: Reply with quote

Did you go back to the thread you departed on ? Provoked some good -er- anecdotes!

Welcome back......
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Thu Jul 15, 2010 10:05 pm    Post subject: Reply with quote

[Withdrawn: it isn't important.]

Last edited by daj95376 on Fri Jul 16, 2010 6:55 am; edited 1 time in total
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Thu Jul 15, 2010 10:16 pm    Post subject: Reply with quote

daj95376 wrote:
I understand your logic, but your chain contains excessive information.

One option is to skip the ANP and use the XY-Chain:

Danny,

I initially noticed the contradiction on 7, then the deletion r8c8<>9. Also, I was pursuing the NP when I found the contradiction, so that is how I posted my finding.

Thanks, Ted
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK

PostPosted: Fri Jul 16, 2010 7:07 am    Post subject: Reply with quote

Mogulmeister wrote:
Did you go back to the thread you departed on ? Provoked some good -er- anecdotes!


I did, I wish I had some strories to tell - but we stayed in a hotel deep in the Andalucian countryside so there were no local colourful bars to watch the game in. There were also a large number of Dutch guests which sort of subdued the Spanish staff!
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Sat Jul 17, 2010 5:02 am    Post subject: Reply with quote

First time it solved with all basics. Second time, all basics. Third time, X-Wing (2) and XY-Wing (256), flightless with pincer transport. I'm sure someone will tell me if I need to make a 4th try.
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