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Nov 17 VH

 
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Clement



Joined: 24 Apr 2006
Posts: 1113
Location: Dar es Salaam Tanzania
PostPosted: Fri Nov 16, 2012 11:02 pm    Post subject: Nov 17 VH Reply with quote
Code:

+-------------+---------+-----------+
| 1   6  23   | 23 4  9 | 8   7  5  |
| 7   45 245  | 6  1  8 | 9   24 3  |
| *248 9  -2348 | -23 5  7 | -246 1  *26 |
+-------------+---------+-----------+
| *24  1  6    | 5  9  3 | 7   8  *24 |
| 9   3  28   | 7  68 4 | 26  5  1  |
| 458 7  458  | 1  68 2 | 3   9  46 |
+-------------+---------+-----------+
| 3   8  9    | 4  2  5 | 1   6  7  |
| 6   45 7    | 8  3  1 | 245 24 9  |
| 45  2  1    | 9  7  6 | 45  3  8  |
+-------------+---------+-----------+
X-Wing on 2 in col 19; r3c347<>2 opens an
XY-Wing 24-28-48 pivoted in r5c3; r3c1<>4, r6c3<>4 solves it.
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George Woods



Joined: 28 Mar 2006
Posts: 304
Location: Dorset UK
PostPosted: Sat Nov 17, 2012 11:13 am    Post subject: another almost an xy! Reply with quote
I didn't spot the x wing in 2s but used the xwing in 4s (cols 2 and 8 ) so r2c3 is not 4 and this set up an amost Xy wing pivoted in r5c3. so if r6c1 is not 4 it becomes 5 via the xy wing 258. else it is 4- so it cannot be 8 so r3c1 is 8 and this solves it! This logic can be tested by setting r6c1 to 8 and in two moves we can see that it is wrong since there is then no 5 in box 4

corrected after reading thecomment below thank you---george

Last edited by George Woods on Sat Nov 17, 2012 5:15 pm; edited 2 times in total
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
PostPosted: Sat Nov 17, 2012 2:42 pm    Post subject: Re: another almost an xy! Reply with quote
George Woods wrote:
I didn't spot the x wing in 2s but used the xwing in 4s (cols 2 and 8 Cool so r2c3 is not 4 and this set up an amost Xy wing pivoted in r5c3. so if r1c6 is not 4 it becomes 5 via the xy wing 258. else it is 4- so it cannot be 8 so r3c1 is 8 and this solves it! This logic can be tested by setting r1c6 to 8 and in two moves we can see that it is wrong since there is then no 5 in box 4


George,

Nice find. I never expected anyone to use an "almost" pattern on this site, but they are easy to spot and very useful. Cool

Your last comment about setting r6c1=8 (you had a typo: r1c6) is sufficient to complete the puzzle; the x-wing(4) is not required.

Ted
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Clement



Joined: 24 Apr 2006
Posts: 1113
Location: Dar es Salaam Tanzania
PostPosted: Sun Nov 18, 2012 1:30 pm    Post subject: Nov 17 VH Reply with quote
George Woods
You have a different Grid from mine after basics?
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George Woods



Joined: 28 Mar 2006
Posts: 304
Location: Dorset UK
PostPosted: Sun Nov 18, 2012 2:14 pm    Post subject: different grid Reply with quote
yes - after the x wing in 4s r2c3 is 25 hence the almost an xy wing and of course I didn't have the removal of 2s from your x wing in 2!
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rebkell



Joined: 18 Nov 2012
Posts: 5
PostPosted: Sun Nov 18, 2012 5:53 pm    Post subject: Re: Nov 17 VH Reply with quote
Clement wrote:
Code:

+-------------+---------+-----------+
| 1   6  23   | 23 4  9 | 8   7  5  |
| 7   45 245  | 6  1  8 | 9   24 3  |
| *248 9  -2348 | -23 5  7 | -246 1  *26 |
+-------------+---------+-----------+
| *24  1  6    | 5  9  3 | 7   8  *24 |
| 9   3  28   | 7  68 4 | 26  5  1  |
| 458 7  458  | 1  68 2 | 3   9  46 |
+-------------+---------+-----------+
| 3   8  9    | 4  2  5 | 1   6  7  |
| 6   45 7    | 8  3  1 | 245 24 9  |
| 45  2  1    | 9  7  6 | 45  3  8  |
+-------------+---------+-----------+
X-Wing on 2 in col 19; r3c347<>2 opens an
XY-Wing 24-28-48 pivoted in r5c3; r3c1<>4, r6c3<>4 solves it.


I'm still having problems solving this after all the x-wing, xy wing I come up with this and I'm just a dunce, but I can't figure out how to solve it from here.

Code:

+------------+--------+------------+
| 1   6  3   | 2 4  9 | 8   7  5   |
| 7   45 245 | 6 1  8 | 9   24 3   |
| 28  9  48  | 3 5  7 | 46  1  246 |
+------------+--------+------------+
| 24  1  6   | 5 9  3 | 7   8  24  |
| 9   3  28  | 7 68 4 | 26  5  1   |
| 458 7  58  | 1 68 2 | 3   9  46  |
+------------+--------+------------+
| 3   8  9   | 4 2  5 | 1   6  7   |
| 6   45 7   | 8 3  1 | 245 24 9   |
| 45  2  1   | 9 7  6 | 45  3  8   |
+------------+--------+------------+
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kuskey



Joined: 10 Dec 2008
Posts: 141
Location: Pembroke, NH
PostPosted: Sun Nov 18, 2012 7:03 pm    Post subject: Nov 17 VH Reply with quote
rebkell:

I see a 458 xy wing with pivot at r3c3 which makes r2c3<>5. This reveals a naked pair <24> in r2, setting r2c2<>4. Barring previous mistakes you should be off and running.
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rebkell



Joined: 18 Nov 2012
Posts: 5
PostPosted: Sun Nov 18, 2012 8:21 pm    Post subject: Re: Nov 17 VH Reply with quote
kuskey wrote:
rebkell:

I see a 458 xy wing with pivot at r3c3 which makes r2c3<>5. This reveals a naked pair <24> in r2, setting r2c2<>4. Barring previous mistakes you should be off and running.


Thanks, that did it, I should have seen that. I wasn't expecting another xy-wing I guess. Embarassed
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Clement



Joined: 24 Apr 2006
Posts: 1113
Location: Dar es Salaam Tanzania
PostPosted: Mon Nov 19, 2012 1:29 pm    Post subject: Nov 17 VH Reply with quote
rebkell wrote
''I'm still having problems solving this after all the x-wing, xy wing I come up with this and I'm just a dunce, but I can't figure out how to solve it from here''.
You are right, an x-wing on 4 in row 46; r9c1<>4 was needed to comlete it. Sorry for the inconvinience Embarassed
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