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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Wed Jun 11, 2014 8:46 am    Post subject: VanHegan 4-16200063 |   |  
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				| Interesting ending.  Something Danny Jones suggested a long time ago. 
 
  	  | Code: |  	  | +-------+-------+-------+
 | . . 2 | . 4 9 | . 7 8 |
 | 9 7 . | . . . | . . . |
 | 8 . 3 | . 2 7 | . . . |
 +-------+-------+-------+
 | . 2 . | . . 3 | 4 . . |
 | . 9 . | . . . | . 2 . |
 | . . 7 | 2 . . | . 1 . |
 +-------+-------+-------+
 | . . . | 1 7 . | 9 . 5 |
 | . . . | . . . | . 8 1 |
 | 7 8 . | 9 6 . | 3 . . |
 +-------+-------+-------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 Keith
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		| JC Van Hay 
 
 
 Joined: 13 Jun 2010
 Posts: 494
 Location: Charleroi, Belgium
 
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				|  Posted: Wed Jun 11, 2014 9:33 am    Post subject: |   |  
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				| [6r8c2=6r8c1-6r1c1=6r1c9-(6=9)r3c9-(9=346)r6c169]-(6=5)r6c2; ste 	  | Code: |  	  | +-----------------+-----------------+-----------------+ | 5(6)  1     2   | 3     4    9    | 5(6)  7   8     |
 | 9     7     56  | 568   158  16   | 2     3   4     |
 | 8     4     3   | 56    2    7    | 1     59  (69)  |
 +-----------------+-----------------+-----------------+
 | 1     2     568 | 5678  589  3    | 4     59  679   |
 | 34    9     568 | 5678  158  146  | 568   2   367   |
 | (34)  5-6   7   | 2     589  (46) | 568   1   (369) |
 +-----------------+-----------------+-----------------+
 | 2     3     4   | 1     7    8    | 9     6   5     |
 | 5(6)  5(6)  9   | 4     3    2    | 7     8   1     |
 | 7     8     1   | 9     6    5    | 3     4   2     |
 +-----------------+-----------------+-----------------+
 
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		| arkietech 
 
 
 Joined: 31 Jul 2008
 Posts: 1834
 Location: Northwest Arkansas USA
 
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				|  Posted: Wed Jun 11, 2014 11:22 am    Post subject: |   |  
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				|  	  | Code: |  	  | *-----------------------------------------------------------* |a56    1     2     | 3     4     9     |b56    7     8     |
 | 9     7     56    | 568   158   16    | 2     3     4     |
 | 8     4     3     | 56    2     7     | 1     59   b69    |
 |-------------------+-------------------+-------------------|
 | 1     2     568   | 5678  589   3     | 4     59    679   |
 | 34    9     568   | 5678  158   146   | 568   2     367   |
 | 34   c56    7     | 2     589  c46    | 568   1    c369   |
 |-------------------+-------------------+-------------------|
 | 2     3     4     | 1     7     8     | 9     6     5     |
 | 5-6  d56    9     | 4     3     2     | 7     8     1     |
 | 7     8     1     | 9     6     5     | 3     4     2     |
 *-----------------------------------------------------------*
 6=5)r1c1-(5=9)r1c7,r3c9-(9=5)r6c269-(5=6)r8c2 => -6r8c1; ste
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Thu Jun 12, 2014 8:09 am    Post subject: |   |  
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				| After basics: 
  	  | Code: |  	  | +----------------+----------------+----------------+ |d56   1    2    | 3    4    9    |e56   7    8    |
 | 9    7    56   | 568  158  16   | 2    3    4    |
 | 8    4    3    | 56   2    7    | 1    59  f69   |
 +----------------+----------------+----------------+
 | 1    2    568  | 5678 589  3    | 4    59   679  |
 | 34   9    568  | 5678 158  146  | 568  2    367  |
 | 34  a56   7    | 2    589  46   | 568  1    3-69 |
 +----------------+----------------+----------------+
 | 2    3    4    | 1    7    8    | 9    6    5    |
 |c56  b56   9    | 4    3    2    | 7    8    1    |
 | 7    8    1    | 9    6    5    | 3    4    2    |
 +----------------+----------------+----------------+
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 Coloring on 6:  af are pincers taking out 6 in R6C9.
 
  	  | Code: |  	  | +----------------+----------------+----------------+ |#56   1    2    | 3    4    9    |*56   7    8    |
 | 9    7    56   | 568  158  16   | 2    3    4    |
 | 8    4    3    | 56   2    7    | 1    59  d69   |
 +----------------+----------------+----------------+
 | 1    2    568  | 5678 589  3    | 4    59   679  |
 | 34   9    568  | 5678 158  146  | 568  2    367  |
 |b34  *56   7    | 2    589 a46   | 568  1   c39   |
 +----------------+----------------+----------------+
 | 2    3    4    | 1    7    8    | 9    6    5    |
 |*56  #56   9    | 4    3    2    | 7    8    1    |
 | 7    8    1    | 9    6    5    | 3    4    2    |
 +----------------+----------------+----------------+
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 Extended XY-wing:  ad are pincers on 6.
 *# Coloring on 5.  * must be 5.
 
 Danny suggested this years ago:  Pincers on 6 here make pincers on 5.
 
 Keith
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Thu Jun 12, 2014 3:24 pm    Post subject: |   |  
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				| I don't know what an Extended XY-Wing is. A-b-c-d looks to be an XY-Chain and transporting the 6 from a to r1c1 solves it. Also don't understand how pincers on 6 create pincers on 5. But then, there's all sorts of stuff I don't understand. 
 (6=5)r1c1-r2c3=r45c3-(5=6)r6c2-(6=4)r6c6-(4=3)r6c1-(3=9)r6c9-(9=6)r3c9=>r1c7<>6
 
 
  	  | Code: |  	  | +----------------+----------------+----------------+ |#56   1    2    | 3    4    9    |*56   7    8    |
 | 9    7    56   | 568  158  16   | 2    3    4    |
 | 8    4    3    | 56   2    7    | 1    59  d69   |
 +----------------+----------------+----------------+
 | 1    2    568  | 5678 589  3    | 4    59   679  |
 | 34   9    568  | 5678 158  146  | 568  2    367  |
 |b34  *56   7    | 2    589 a46   | 568  1   c39   |
 +----------------+----------------+----------------+
 | 2    3    4    | 1    7    8    | 9    6    5    |
 |*56  #56   9    | 4    3    2    | 7    8    1    |
 | 7    8    1    | 9    6    5    | 3    4    2    |
 +----------------+----------------+----------------+
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Thu Jun 12, 2014 10:36 pm    Post subject: |   |  
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				| Marty, 
 If pincers on 6 both see cells 56, those 56 cells must be pincers on 5.
 
 Keith
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Fri Jun 13, 2014 1:54 am    Post subject: |   |  
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				| OK, Thanks, I think I understand. |  | 
	
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		| arkietech 
 
 
 Joined: 31 Jul 2008
 Posts: 1834
 Location: Northwest Arkansas USA
 
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				|  Posted: Fri Jun 13, 2014 2:18 am    Post subject: |   |  
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				|  	  | keith wrote: |  	  | Marty, 
 If pincers on 6 both see cells 56, those 56 cells must be pincers on 5.
 
 Keith
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 What if both pincers were 6?
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Fri Jun 20, 2014 7:49 am    Post subject: |   |  
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				|  	  | arkietech wrote: |  	  |  	  | keith wrote: |  	  | Marty, 
 If pincers on 6 both see cells 56, those 56 cells must be pincers on 5.
 
 Keith
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 What if both pincers were 6?
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 The logic is, one or both pincers are 6.  If they each see a cell 56, then one or both of those 56 cells is 5.  They are pincers on 5.
 
 There is a more subtle discussion if it is known that one, but not both, of the pincers is 6.  You get into the possibility that the 56 cells are a remote pair, which is not the case here.
 
 In this case, we know the 56 cells are the same:  They must both be 5.
 
 Keith
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