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		| ZeroAssoluto 
 
 
 Joined: 05 Feb 2017
 Posts: 1019
 Location: Rimini, Italy
 
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				|  Posted: Mon Oct 31, 2022 8:54 am    Post subject: Oct 31 VH |   |  
				| 
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				| Hi everyone, 
 
  	  | Code: |  	  | +-------+-------------+----------+
 | 3 8 2 | 167 67  156 | 4  9  56 |
 | 6 4 9 | 28  238 35  | 7  1  25 |
 | 7 1 5 | 4   269 69  | 8  3  26 |
 +-------+-------------+----------+
 | 8 7 6 | 9   1   2   | 5  4  3  |
 | 5 2 3 | 67  467 46  | 1  8  9  |
 | 4 9 1 | 3   5   8   | 26 26 7  |
 +-------+-------------+----------+
 | 1 3 4 | 5   26  7   | 9  26 8  |
 | 9 5 8 | 26  34  34  | 26 7  1  |
 | 2 6 7 | 18  89  19  | 3  5  4  |
 +-------+-------------+----------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 
  	  | Quote: |  	  | in only one step if r3c6=6 -6 in r1c456,r3c9
 if r3c6=9 r9c5=9 r2c5=8 r2c6=3 r1c6=5 r1c9=6 and -6 in r1c456,r3c9
 or
 if r1c6=5 -5 in r1c9,r2c6
 if r1c6=-5 r2c6=5 r2c5=3 r9c5=8 r3c5=9 r3c9=2 r2c9=5 and -5 in r2c6,r1c9
 or
 if r2c4=2 -2 in r2c9,r3c5
 if r2c4=8 r9c5=8 r3c5=9 r3c9=2 and -2 in r2c9,r3c5
 or with 2 steps classical
 W-Wing 6,7 in r1c5,r5c4 SL with number 6 in r7c5,r8c4 and -7 in r1c4,r5c5
 and
 XY-Wing 1,6,9 in r1c4,r39c6 and -1 in r1c6,r9c4
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 Ciao Gianni
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		| TomC 
 
 
 Joined: 30 Oct 2020
 Posts: 359
 Location: Wales
 
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				|  Posted: Mon Oct 31, 2022 11:53 am    Post subject: |   |  
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				| Remove <6> from r3c6 to solve 
 
  	  | Code: |  	  | +-------+---------------+------------+
 | 3 8 2 | 167 67    156 | 4   9   56 |
 | 6 4 9 | 28  238  c35  | 7   1  b25 |
 | 7 1 5 | 4   269  x69  | 8   3  a26 |
 +-------+---------------+------------+
 | 8 7 6 | 9   1     2   | 5   4   3  |
 | 5 2 3 | 67  467  e46  | 1   8   9  |
 | 4 9 1 | 3   5     8   | 26  26  7  |
 +-------+---------------+------------+
 | 1 3 4 | 5   26    7   | 9   26  8  |
 | 9 5 8 | 26  34   d34  | 26  7   1  |
 | 2 6 7 | 18  89    19  | 3   5   4  |
 +-------+---------------+------------+
 
 | 
 Two ways to look at this:
 
 If x=6, a=2, b=5, c=3 leads to <4> in both d+e
 or
 XY chain abcde gives pincers of <6> in a + e to remove <6> from x
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		| dongrave 
 
 
 Joined: 06 Mar 2014
 Posts: 572
 
 
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				|  Posted: Mon Oct 31, 2022 1:35 pm    Post subject: |   |  
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				| I used the 269 XYZ-Wing r3c56,r7c5 (-6r1c5) which opened up the 69-1 XY-Wing r1c4,r39c6 (-1r1c6, -1r9c4). |  |  
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		| TomC 
 
 
 Joined: 30 Oct 2020
 Posts: 359
 Location: Wales
 
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				|  Posted: Tue Nov 01, 2022 1:31 pm    Post subject: |   |  
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				| You can make the same eliminations as the 69-1 XY-wing but not use the XYZ-wing first 
 
  	  | Code: |  	  | +-------+------------------+------------+
 | 3 8 2 | a167 b67    x156 | 4   9   56 |
 | 6 4 9 |  28   238    35  | 7   1   25 |
 | 7 1 5 |  4    269   c69  | 8   3   26 |
 +-------+------------------+------------+
 | 8 7 6 |  9    1      2   | 5   4   3  |
 | 5 2 3 |  67   467    46  | 1   8   9  |
 | 4 9 1 |  3    5      8   | 26  26  7  |
 +-------+------------------+------------+
 | 1 3 4 |  5    26     7   | 9   26  8  |
 | 9 5 8 |  26   34     34  | 26  7   1  |
 | 2 6 7 | x18   89    d19  | 3   5   4  |
 +-------+------------------+------------+
 
 | 
 
 If x=1, ab=<67>, c=9, d=1
 
 Or using c as the pivot
 if c=6, b=7, a=1
 if c=9, d=1
 
 This gives pincers on <1> in a+d to remove <1> from x
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		| dongrave 
 
 
 Joined: 06 Mar 2014
 Posts: 572
 
 
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				|  Posted: Tue Nov 01, 2022 9:09 pm    Post subject: |   |  
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				| Hi Gianni!  When you said 'classical steps' I thought that you were referring to just VH moves because many years ago Marty told me that every VH puzzle on this site could be solved by using just the 3 classical wing moves X-Wing, XY-Wing, and XYZ-Wing.  Since then I have only considered using VH moves when solving any VH puzzle on this site.  When I suggested to Marty that we refer to this as the 'official solution' he really didn't like it and suggested instead that we refer to it as the 'standard solution'.  I like his suggestion. |  |  
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