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au tough June 19, 2012

 
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arkietech



Joined: 31 Jul 2008
Posts: 1708
Location: Northwest Arkansas USA

PostPosted: Tue Jun 19, 2012 5:39 am    Post subject: au tough June 19, 2012 Reply with quote

Code:

 *-----------*
 |9..|3..|...|
 |...|.5.|.4.|
 |185|...|9..|
 |---+---+---|
 |.3.|..6|...|
 |2..|.3.|..7|
 |...|8..|.2.|
 |---+---+---|
 |..7|...|519|
 |.4.|.7.|...|
 |...|..9|..8|
 *-----------*
 

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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Tue Jun 19, 2012 2:36 pm    Post subject: Reply with quote

An extended WXYZ-Wing solves it...

/SudoQ
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arkietech



Joined: 31 Jul 2008
Posts: 1708
Location: Northwest Arkansas USA

PostPosted: Tue Jun 19, 2012 2:44 pm    Post subject: Reply with quote

SudoQ wrote:
An extended WXYZ-Wing solves it...


Help me with your wxyz wing. Confused

Here is a fancy xy-wing
Code:

 *--------------------------------------------------------------------*
 | 9      267    4      | 3      168    128    | 12678  58     1256   |
 | 36     267    23     | 9      5      128    | 12678  4      126    |
 | 1      8      5      | 467    46     247    | 9      36     236    |
 |----------------------+----------------------+----------------------|
 | 47     3      18     | 257    29     6      | 18     59     45     |
 | 2     a59     168    |b145    3     b145    | 168    589    7      |
 | 47     5-9    16     | 8     c19     157    | 136    2      13456  |
 |----------------------+----------------------+----------------------|
 | 68     26     7      | 246    2468   3      | 5      1      9      |
 | 58     4      9      | 15     7      158    | 236    36     236    |
 | 356    1      23     | 256    26     9      | 4      7      8      |
 *--------------------------------------------------------------------*
(9=5)r5c2-(5=14)r5c46-(1=9)r6c5 => -9r6c2; stte

either r5c2 or r6c5 must be a 9


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Last edited by arkietech on Tue Jun 19, 2012 4:11 pm; edited 1 time in total
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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Tue Jun 19, 2012 3:29 pm    Post subject: Reply with quote

arkietech wrote:

Help me with your wxyz wing. Confused

Your solution seems to be identical to the one I found.
I also tried the puzzle in the XSUDO solver program
that showed a similar pattern, called "Extended WXYZ-Wing":
Code:
|---------------|----------------|-------------------|
| 9    267  4   | 3    168   128 | 12678  58   1256  |
| 36   267  23  | 9    5     128 | 12678  4    126   |
| 1    8    5   | 467  46    247 | 9      36   236   |
|---------------|----------------|-------------------|
| 47   3    18  | 257  29    6   | 18     59   45    |
| 2    9-5  168 |(145) 3    (145)| 168    589  7     |
| 47  (59)  16  | 8   (19)  17-5 | 136    2    13456 |
|---------------|----------------|-------------------|
| 68   26   7   | 246  2468  3   | 5      1    9     |
| 58   4    9   | 15   7     158 | 236    36   236   |
| 356  1    23  | 256  26    9   | 4      7    8     |
|---------------|----------------|-------------------|

/SudoQ
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arkietech



Joined: 31 Jul 2008
Posts: 1708
Location: Northwest Arkansas USA

PostPosted: Tue Jun 19, 2012 4:23 pm    Post subject: Reply with quote

SudoQ wrote:
Your solution seems to be identical to the one I found.
I also tried the puzzle in the XSUDO solver program
that showed a similar pattern, called "Extended WXYZ-Wing":

(5=9)r6c2-(9=1)r6c5-(1=45)r5c46 => -5r6c2,r6c6; stte

A little different. I still don't see the "extended"
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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Tue Jun 19, 2012 4:53 pm    Post subject: Reply with quote

arkietech wrote:
A little different. I still don't see the "extended"

Me neither!
I borrowed the name from XSUDO, so I thought it was correct... Embarassed

/SudoQ
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arkietech



Joined: 31 Jul 2008
Posts: 1708
Location: Northwest Arkansas USA

PostPosted: Tue Jun 19, 2012 5:16 pm    Post subject: Reply with quote

Extended must mean "extended form" Here is a guess
Code:

.-----------.----------.----------.
| *  *  WXYZ| .  XZ .  | YZ .  .  |
| .  WZ .   | .  .  .  | .  .  .  |
| .  .  .   | .  .  .  | .  .  .  |
:-----------+----------+----------:

In a standard WXYZ-wing the pivot has the candidates WXYZ. In all possible options for the pivot cell, Z will be eliminated from the starred cells.

Extended form of the WXYZ-Wing
Code:

.-----------.----------.----------.
| *  *  *   |XYZ . XYZ | .  .  .  |
| .  WZ .   | *  WX *  | .  .  .  |
| .  .  .   | .  .  .  | .  .  .  |
:-----------+----------+----------:

Z'S can be removed from starred cells
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Tue Jun 19, 2012 10:17 pm    Post subject: Reply with quote

I don't agree with any of the "names" submitted for the two patterns under discussion for this grid.

Accepting that a wing is any chain with three strong links separated by two weak links. At best, what I see are two wings with a single ALS strong link in each.

Code:
 Wing with an ALS for the pseudo-vertex cell:
 +-----------------------------------------------------------------------+
 |  9      267    4      |  3      168    128    |  12678  58     1256   |
 |  36     267    23     |  9      5      128    |  12678  4      126    |
 |  1      8      5      |  467    46     247    |  9      36     236    |
 |-----------------------+-----------------------+-----------------------|
 |  47     3      18     |  257    29     6      |  18     59     45     |
 |  2     (59)    168    | (145)   3     (145)   |  168    589    7      |
 |  47     5-9    16     |  8     (19)    157    |  136    2      13456  |
 |-----------------------+-----------------------+-----------------------|
 |  68     26     7      |  246    2468   3      |  5      1      9      |
 |  58     4      9      |  15     7      158    |  236    36     236    |
 |  356    1      23     |  256    26     9      |  4      7      8      |
 +-----------------------------------------------------------------------+
 # 87 eliminations remain

 (9=5)r5c2 - (54=41)r5c46 - (1=9)r6c5  =>  r6c2<>9

Code:
 Wing with an ALS for a pseudo-pincer cell:
 +-----------------------------------------------------------------------+
 |  9      267    4      |  3      168    128    |  12678  58     1256   |
 |  36     267    23     |  9      5      128    |  12678  4      126    |
 |  1      8      5      |  467    46     247    |  9      36     236    |
 |-----------------------+-----------------------+-----------------------|
 |  47     3      18     |  257    29     6      |  18     59     45     |
 |  2      9-5    168    | (145)   3     (145)   |  168    589    7      |
 |  47    (59)    16     |  8     (19)    17-5   |  136    2      13456  |
 |-----------------------+-----------------------+-----------------------|
 |  68     26     7      |  246    2468   3      |  5      1      9      |
 |  58     4      9      |  15     7      158    |  236    36     236    |
 |  356    1      23     |  256    26     9      |  4      7      8      |
 +-----------------------------------------------------------------------+
 # 87 eliminations remain

 (5=9)r6c2 - (9=1)r6c5 - (1=45)r5c46  =>  r5c2,r6c6<>5


As an aside point:

Here's what I consider to be the proper notation for reading the first chain from l-to-r:

Code:
 (9=5)r5c2 - (5=41)r5c46 - (1=9)r6c5  =>  r6c2<>9

However, here's what I consider to be the proper notation for reading the first chain from r-to-l:

Code:
 (9=5)r5c2 - (54=1)r5c46 - (1=9)r6c5  =>  r6c2<>9

If this chain had been part of a loop, then we have a scenario where the ALS quasi-resembles an ERI (Empty Rectangle Intersection) with two interpretations. That's why I wrote the first chain the way I did.
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ronk



Joined: 07 May 2006
Posts: 397

PostPosted: Wed Jun 20, 2012 10:01 pm    Post subject: Reply with quote

daj95376 wrote:
I don't agree with any of the "names" submitted for the two patterns under discussion for this grid.

Accepting that a wing is any chain with three strong links separated by two weak links. At best, what I see are two wings with a single ALS strong link in each.

I think the wxyz-wing and extended wxyz-wing terms are OK for these two patterns. These names pre-dated the use of the wing term for patterns with three strong links, except for the xy-wing, of course.
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Thu Jun 21, 2012 3:15 am    Post subject: Reply with quote

[Withdrawn: I've been working from a misconception of *-Wing for a very long time. My apologies.]

Last edited by daj95376 on Thu Jun 21, 2012 4:36 pm; edited 1 time in total
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aran



Joined: 19 Apr 2010
Posts: 70

PostPosted: Thu Jun 21, 2012 3:53 pm    Post subject: Reply with quote

daj95376 wrote:
ronk wrote:
I think the wxyz-wing and extended wxyz-wing terms are OK for these two patterns. These names pre-dated the use of the wing term for patterns with three strong links, except for the xy-wing, of course.

Well, I'm not buying it. A WXYZ-Wing -- even extended -- should have four distinct candidate values in the vertex ... and none of these patterns qualify.

Given that all XY XYZ WXYZ wings are particular instances of ALS X-Z logic, the important notion would seem to be ALS rather than the actual distribution of the ALS candidates over the ALS cells.
Under this view, there would be no requirement for any vertex cell in a WXYZ to contain all 4 candidates, nor any need to draw a distinction between WXYZ and extended-WXYZ, all that changes being the distribution of the same candidates over the same cells.
Accordingly under this approach, the above :
{1459}r5c246
{19}r6c5
ie {9451} {19} =><9>r6c2
would qualify as WXYZ.
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