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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Wed Jan 18, 2017 6:05 am    Post subject: Jan 18 VH |   |  
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				|  	  | Code: |  	  | +-----------+---------+-----------+
 | 6  4   9  | 2  3  5 | 1   8 7   |
 | 8  2   7  | 6  9  1 | 4   3 5   |
 | 5  1   3  | 4  7  8 | 9   2 6   |
 +-----------+---------+-----------+
 | 7  5   4  | 8  2  6 | 3   9 1   |
 | 13 38  2  | 9  14 7 | 6   5 48  |
 | 9  6   18 | 5  14 3 | 28  7 248 |
 +-----------+---------+-----------+
 | 4  378 18 | 17 58 9 | 258 6 238 |
 | 2  89  5  | 3  6  4 | 7   1 89  |
 | 13 379 6  | 17 58 2 | 58  4 39  |
 +-----------+---------+-----------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 
  	  | Quote: |  	  | X-Wing  (8) r58=> -8r7c29 exposes an XYZ-Wing (379) hinged in r9c2=> -3 r9c1 | 
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		| hughwill 
 
 
 Joined: 05 Apr 2010
 Posts: 424
 Location: Birmingham UK
 
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				|  Posted: Wed Jan 18, 2017 11:26 am    Post subject: Jan 18 VH |   |  
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				| Couldn't see the X wing for the life of me. But there's also an alternative 13-7 XY wing to see it off (pivot r9c1)
 Hugh
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		| Earl 
 
 
 Joined: 30 May 2007
 Posts: 677
 Location: Victoria, KS
 
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				|  Posted: Wed Jan 18, 2017 2:26 pm    Post subject: Jan 18 VH |   |  
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				| unique rectangle 58(R79,C57); R7C7 = 2 
 Early Earl
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		| George Woods 
 
 
 Joined: 28 Mar 2006
 Posts: 304
 Location: Dorset UK
 
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				|  Posted: Wed Jan 18, 2017 4:53 pm    Post subject: XY chain? |   |  
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				| pivoting at r9c1 creates wings (of 9) at r9c9 and r8c2 so r8c9 <>9 Is this what is described as an xy chain or what?
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Wed Jan 18, 2017 9:30 pm    Post subject: |   |  
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				| George, 
 Yes.  This is a short XY chain, but you did not mention using R7C3.
 
 
  	  | Code: |  	  | +-----------+---------+-----------+ | 6  4   9  | 2  3  5 | 1   8 7   |
 | 8  2   7  | 6  9  1 | 4   3 5   |
 | 5  1   3  | 4  7  8 | 9   2 6   |
 +-----------+---------+-----------+
 | 7  5   4  | 8  2  6 | 3   9 1   |
 | 13 38  2  | 9  14 7 | 6   5 48  |
 | 9  6   18 | 5  14 3 | 28  7 248 |
 +-----------+---------+-----------+
 | 4  378 18c| 17 58 9 | 258 6 238 |
 | 2  89d 5  | 3  6  4 | 7   1 8-9 |
 |13b 379 6  | 17 58 2 | 58  4 39a |
 +-----------+---------+-----------+
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 If a is 3 ...
 The X-wing on 8 is in R58.
 
 Keith
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