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		| roaa 
 
 
 Joined: 18 Apr 2009
 Posts: 112
 Location: Sweden
 
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				|  Posted: Wed Jan 18, 2012 7:39 am    Post subject: Jan 18 VH |   |  
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				| Where is Clement? The xy-wing 169 with pivot at r2c9 solved it for me.
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		| Rocky Mozell 
 
 
 Joined: 28 Jul 2010
 Posts: 34
 Location: Boston, MA
 
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				|  Posted: Wed Jan 18, 2012 3:38 pm    Post subject: |   |  
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				| I had a skyscraper on 9 in boxes 2 and 3. |  | 
	
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Wed Jan 18, 2012 5:43 pm    Post subject: |   |  
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				|  	  | Rocky Mozell wrote: |  	  | I had a skyscraper on 9 in boxes 2 and 3. | 
 Rocky, I wasn't able to get rid of the 9 in r1c1.
 
 
  	  | Code: |  	  | +-------------+---------+-----------+
 | 459 45  8   | 3  1 69 | 7  2  569 |
 | 6   3   19  | 2  5 7  | 48 48 19  |
 | 125 57  127 | 8  4 69 | 69 15 3   |
 +-------------+---------+-----------+
 | 7   2   6   | 5  9 18 | 3  18 4   |
 | 14  8   14  | 7  6 3  | 5  9  2   |
 | 3   9   5   | 4  2 18 | 68 7  16  |
 +-------------+---------+-----------+
 | 249 46  249 | 69 8 5  | 1  3  7   |
 | 59  567 79  | 1  3 2  | 49 46 8   |
 | 8   1   3   | 69 7 4  | 2  56 59  |
 +-------------+---------+-----------+
 
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 Play this puzzle online at the Daily Sudoku site
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		| eddieg 
 
 
 Joined: 12 Jan 2006
 Posts: 47
 Location: San Diego, CA USA
 
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				|  Posted: Wed Jan 18, 2012 8:27 pm    Post subject: |   |  
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				| From above sample, see the 69 and 19 in Box 3, and the 16 in Box 6.  Makes an easy XYZ-Wing that eliminates the 6 in R6C7, and then the rest falls into place. 
 I don't even know what a skycrapper is. I am able (sometimes it takes a while) to finish all of the VH puzzles with basic moves.
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		| Luke451 
 
 
 Joined: 20 Apr 2008
 Posts: 310
 Location: Southern Northern California
 
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				|  Posted: Wed Jan 18, 2012 10:07 pm    Post subject: |   |  
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				|  	  | eddieg wrote: |  	  | From above sample, see the 69 and 19 in Box 3, and the 16 in Box 6.  Makes an easy XYZ-Wing that eliminates the 6 in R6C7, and then the rest falls into place. | 
  	  | Code: |  	  | +-------------+---------+-----------+ | 459 45  8   | 3  1 69 | 7  2  569 |
 | 6   3   19  | 2  5 7  | 48 48 19  |
 | 125 57  127 | 8  4 69 | 69 15 3   |
 +-------------+---------+-----------+
 | 7   2   6   | 5  9 18 | 3  18 4   |
 | 14  8   14  | 7  6 3  | 5  9  2   |
 | 3   9   5   | 4  2 18 | 68 7  16  |
 +-------------+---------+-----------+
 | 249 46  249 | 69 8 5  | 1  3  7   |
 | 59  567 79  | 1  3 2  | 49 46 8   |
 | 8   1   3   | 69 7 4  | 2  56 59  |
 +-------------+---------+-----------+
 
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 Good spot, that does it. I don't think it's called an xyz-wing unless all three digits appear in that central pivot cell.
 
 That there is an xy-wing, shortest possible xy-chain.
 
 
  	  | Quote: |  	  | I don't even know what a skycrapper is. | 
 A skyscraper ( only one "p"
  ) is a single digit technique using the same basic notion as your xy-wing. Click  here  for the Sudopedia article. |  | 
	
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		| Rocky Mozell 
 
 
 Joined: 28 Jul 2010
 Posts: 34
 Location: Boston, MA
 
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				|  Posted: Fri Jan 20, 2012 3:17 pm    Post subject: |   |  
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				| Rocky, I wasn't able to get rid of the 9 in r1c1. 
 Neither was I. What a dope.
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		| TerenceF 
 
 
 Joined: 21 Dec 2007
 Posts: 26
 Location: Takapuna, NZ
 
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				|  Posted: Mon Jan 23, 2012 12:14 am    Post subject: |   |  
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				| Similarly there is a 159 XY wing pivoted at r9c9 (using the 19 and 15 in Box 3) which can be used to eliminate the 5 from r9c8 
 Apologies if the technical wording is wrong, I'm only an occasional...
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Mon Jan 23, 2012 12:49 am    Post subject: |   |  
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				|  	  | TerenceF wrote: |  	  | Similarly there is a 159 XY wing pivoted at r9c9 (using the 19 and 15 in Box 3) which can be used to eliminate the 5 from r9c8 
 Apologies if the technical wording is wrong, I'm only an occasional...
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 Terence, the pivot is the 19 cell in r2c9 since that is the cell that sees the other two cells.
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