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hughwill
Joined: 05 Apr 2010
Posts: 424
Location: Birmingham UK
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 Posted: Sun Dec 06, 2015 10:37 am Post subject: Dec 6 VH |
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| Code: |
+---------+-------------+-------------+
| 8 9 3 | 4 2 1 | 7 5 6 |
| 25 1 7 | 35 359 6 | 239 4 8 |
| 25 4 6 | 8 7 359 | 239 239 1 |
+---------+-------------+-------------+
| 79 3 8 | 257 59 259 | 1 6 4 |
| 79 6 5 | 1 4 8 | 239 2379 39 |
| 1 2 4 | 37 6 39 | 8 79 5 |
+---------+-------------+-------------+
| 6 8 12 | 25 15 7 | 4 39 39 |
| 4 5 12 | 9 13 23 | 6 8 7 |
| 3 7 9 | 6 8 4 | 5 1 2 |
+---------+-------------+-------------+
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Play this puzzle online at the Daily Sudoku site
Two steps today (unless anyone knows better!) (Select quote to view)
| Quote: | 25-3 XY wing pivot r7c4 opening 59-3 XY wing pivot
r3c6. Then r6c4=7 and all fall |
Hugh |
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Clement
Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania
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| Posted: Sun Dec 06, 2015 3:07 pm Post subject: Dec 6 VH |
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| Code: |
+---------+-------------+-------------+
| 8 9 3 | 4 2 1 | 7 5 6 |
| 25 1 7 | 35 359 6 | 239 4 8 |
| 25 4 6 | 8 7 359 | 239 239 1 |
+---------+-------------+-------------+
| e7-9 3 8 | d257 a59 259 | 1 6 4 |
| 79 6 5 | 1 4 8 | 239 2379 39 |
| 1 2 4 | 37 6 39 | 8 79 5 |
+---------+-------------+-------------+
| 6 8 12 | c25 b15 7 | 4 39 39 |
| 4 5 12 | 9 13 23 | 6 8 7 |
| 3 7 9 | 6 8 4 | 5 1 2 |
+---------+-------------+-------------+
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5r4c5 - r7c5 = (5-2)r7c4 = (2-7)r4c4 = (7)r4c1 => -9r4c1; stte |
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rmireland
Joined: 21 Sep 2013
Posts: 33
Location: New Orleans
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| Posted: Sun Dec 06, 2015 4:41 pm Post subject: |
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Hi Clement,
I think there may be a mistake somewhere, maybe a typo, but setting 5r4c5 does not lead me to a solution.
Rick |
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dongrave
Joined: 06 Mar 2014
Posts: 568
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| Posted: Sun Dec 06, 2015 6:46 pm Post subject: |
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| rmireland wrote: | Hi Clement,
I think there may be a mistake somewhere, maybe a typo, but setting 5r4c5 does not lead me to a solution.
Rick |
Hi rmireland, I just learned recently about chains like Clement's from Marty. The chain that he lists begins and ends with pincers so it proves that regardless of the value at r4c5, r4c1 cannot be 9. It goes like this. If r4c5 is 9, then r4c1 obviously can't be 9 - and if r4c5 is not 9, then it's 5 in which case his chain shows you that r4c1 is still not 9. Pretty cool, isn't it? I use these as often as possible now when solving Evil puzzles from 1sudoku.net. Don. |
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Clement
Joined: 24 Apr 2006
Posts: 1111
Location: Dar es Salaam Tanzania
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| Posted: Mon Dec 07, 2015 6:25 am Post subject: Dec 6 VH |
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| dongrave wrote: | | rmireland wrote: | Hi Clement,
I think there may be a mistake somewhere, maybe a typo, but setting 5r4c5 does not lead me to a solution.
Rick |
Hi rmireland, I just learned recently about chains like Clement's from Marty. The chain that he lists begins and ends with pincers so it proves that regardless of the value at r4c5, r4c1 cannot be 9. It goes like this. If r4c5 is 9, then r4c1 obviously can't be 9 - and if r4c5 is not 9, then it's 5 in which case his chain shows you that r4c1 is still not 9. Pretty cool, isn't it? I use these as often as possible now when solving Evil puzzles from 1sudoku.net. Don. |
Your quite right dongrave. |
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dongrave
Joined: 06 Mar 2014
Posts: 568
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| Posted: Tue Dec 08, 2015 1:21 am Post subject: |
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Thanks Clement! I'm learning from the best right here on this site. I don't have to list your names. I'm sure you all know who you are - except for maybe Marty who denies being an expert (He's not an expert? Chuckle! Yeah, right.)
I recently tried learning a 'fish' solving method that Keith explained to me but it looks like all of the 'Evil' puzzles that I've solved so far from 1sudoku.com can't be solved using 'fish' solutions so I ended up using forcing chains for every one of them (although some were simple coloring). And most of the time I was able to represent them with pincers on both ends. They're the best! I recently learned about them from Marty and Bat. |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Tue Dec 08, 2015 3:30 am Post subject: |
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| Fish are difficult for me, except for X-Wings. I've posted a number of times that I don't look for Swordfish because it's too much effort for too little return. |
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