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		| arkietech 
 
 
 Joined: 31 Jul 2008
 Posts: 1834
 Location: Northwest Arkansas USA
 
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				|  Posted: Wed Jul 11, 2012 6:56 am    Post subject: au tough July 11, 2012 |   |  
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				|  	  | Code: |  	  | *-----------*
 |.19|...|..2|
 |..3|.1.|...|
 |...|9.5|...|
 |---+---+---|
 |4.2|.9.|...|
 |8..|...|..5|
 |...|.6.|9.7|
 |---+---+---|
 |...|7.8|...|
 |...|.3.|4..|
 |7..|...|13.|
 *-----------*
 
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 Play online
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		| arkietech 
 
 
 Joined: 31 Jul 2008
 Posts: 1834
 Location: Northwest Arkansas USA
 
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				|  Posted: Wed Jul 11, 2012 9:22 pm    Post subject: |   |  
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				|  	  | Code: |  	  | *--------------------------------------------------------------------* | 56     1      9      | 34     78     34     | 5678   568    2      |
 | 25     78     3      | 26     1      267    | 578    9      4      |
 | 26     478    478    | 9      278    5      | 3678   168    13     |
 |----------------------+----------------------+----------------------|
 | 4      67     2      | 5      9      137    | 368    168    13     |
 | 8      9     a67     | 34    a27     1347-2 | 236    1246   5      |
 | 13     35    b15     | 8      6      4-2    | 9      24     7      |
 |----------------------+----------------------+----------------------|
 | 13     36    b16     | 7      4      8      | 25     25     9      |
 | 9      258   c58     | 1      3     c26     | 4      7     c68     |
 | 7      248    48     | 26     5      9      | 1      3      68     |
 *--------------------------------------------------------------------*
 (27=6)r5c35-(61=5)r67c3-(568=2)r8c369 => -2r56c6; stte
 
 either r5c5 is a 2 or r8c6 is a 2
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Thu Jul 12, 2012 12:15 am    Post subject: |   |  
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				| I tried it but gave up. |  | 
	
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		| arkietech 
 
 
 Joined: 31 Jul 2008
 Posts: 1834
 Location: Northwest Arkansas USA
 
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				|  Posted: Thu Jul 12, 2012 1:12 am    Post subject: |   |  
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				|  	  | Marty R. wrote: |  	  | I tried it but gave up. | 
 
 did you see the ur on 34?
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Thu Jul 12, 2012 3:40 am    Post subject: |   |  
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				| I had missed the quad in box 2. After that I played the34 UR and then I eliminated one digit (unhelpful) based on the 48 DP. That left me here without a further move. 
 
  	  | Code: |  	  | +------------+------------+--------------+
 | 56 1   9   | 34 78  34  | 5678 568  2  |
 | 25 78  3   | 26 1   267 | 578  9    4  |
 | 26 478 478 | 9  278 5   | 3678 168  13 |
 +------------+------------+--------------+
 | 4  67  2   | 5  9   137 | 368  168  13 |
 | 8  9   67  | 34 27  127 | 236  1246 5  |
 | 13 35  15  | 8  6   24  | 9    24   7  |
 +------------+------------+--------------+
 | 13 36  16  | 7  4   8   | 25   25   9  |
 | 9  258 58  | 1  3   26  | 4    7    68 |
 | 7  24  48  | 26 5   9   | 1    3    68 |
 +------------+------------+--------------+
 
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 Play this puzzle online at the Daily Sudoku site
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		| daj95376 
 
 
 Joined: 23 Aug 2008
 Posts: 3854
 
 
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				|  Posted: Sun Jul 15, 2012 3:51 pm    Post subject: |   |  
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				| Marty, oooooh so close. All you need is a simple 7-cell XY-Chain. _  _ 
 (2=7)r5c5 =6r5c3 =7r4c2 =4r3c2 =2r9c2 =6r9c4 - (6=2)r8c6  =>  r6c6<>2
 
 BTW: Nice catch on the 48-UR elimination. It exposed the XY-Chain.
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Sun Jul 15, 2012 5:47 pm    Post subject: |   |  
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				|  	  | daj95376 wrote: |  	  | Marty, oooooh so close. All you need is a simple 7-cell XY-Chain. _  _ 
 (2=7)r5c5 =6r5c3 =7r4c2 =4r3c2 =2r9c2 =6r9c4 - (6=2)r8c6  =>  r6c6<>2
 
 BTW: Nice catch on the 48-UR elimination. It exposed the XY-Chain.
 | 
 In that case, how about after basics:
 
  	  | Code: |  	  | +-------------------+-------------------+-------------------+ | 56    1     9     | 34    78    34    | 5678  568   2     |
 | 25    78    3     | 26    1     267   | 578   9     4     |
 | 26    478   478   | 9     278   5     | 3678  168   13    |
 +-------------------+-------------------+-------------------+
 | 4     67    2     | 5     9     137   | 368   168   13    |
 | 8     9    b67    | 34   a27    12347 | 236   1246  5     |
 | 13    35   d15    | 8     6    -24    | 9     24    7     |
 +-------------------+-------------------+-------------------+
 | 13    36   c16    | 7     4     8     | 25    25    9     |
 | 9     258  e58    | 1     3    g26    | 4     7    f68    |
 | 7     248   48    | 26    5     9     | 1     3     68    |
 +-------------------+-------------------+-------------------+
 | 
 Keith
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		| daj95376 
 
 
 Joined: 23 Aug 2008
 Posts: 3854
 
 
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				|  Posted: Sun Jul 15, 2012 7:59 pm    Post subject: |   |  
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				|  	  | keith wrote: |  	  | In that case, how about after basics: 
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 Yes, that works fine. It also performs r5c6<>2, something that I forgot to address in my solution as well.
 
 Originally, I was intrigued to see what was blocking Marty's progress. While examining my solver's default solution, which places URs before chains, I noticed that my solver's solution almost exactly matched Marty's solution. So, I just indicated what he could use as a next step.
 
 Regards, Danny
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