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Puzzle 10/09/21: B

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Tue Sep 21, 2010 4:56 am    Post subject: Puzzle 10/09/21: B Reply with quote

Code:
 +-----------------------+
 | 7 . . | 4 . . | 3 . . |
 | . 9 3 | 8 7 . | 4 . . |
 | . 4 6 | . 3 . | . . . |
 |-------+-------+-------|
 | 9 3 . | 5 1 . | 8 . 7 |
 | . 8 5 | 6 2 7 | . . . |
 | . . . | . 8 . | . . . |
 |-------+-------+-------|
 | 2 5 . | 1 . . | 6 3 . |
 | . . . | . . . | 7 2 . |
 | . . . | 7 . . | . . 5 |
 +-----------------------+

Play this puzzle online at the Daily Sudoku site
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JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium

PostPosted: Tue Sep 21, 2010 8:04 am    Post subject: Reply with quote

Quote:
4-SIS AIC : (94)R5C8 (41)R5C1 1C3 8R1 : (9)r5c8=(8)r1c8 : => r1c8<>9

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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK

PostPosted: Tue Sep 21, 2010 11:33 am    Post subject: Reply with quote

A wing...
Quote:
m-wing(48) (4=8)r8c1 - r9c3=(8-4)r9c8=r5c8 ; r5c1<>4
.. or the corresponding ...
s-wing(48) (4)r5c8=r5c1 - (4=8)r8c1 - (8)r9c3=r9c8 ; r9c8<>4
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Tue Sep 21, 2010 7:26 pm    Post subject: Reply with quote

Updated information originally provided by storm_norm.

Code:
Three Strong, Two Weak, Inference Set:   3-SIS/2-WIS
_______________________________________________________________________________________

               =     -     =     -     =

fishy:      A  =  A  -  A  =  A  -  A  =   A   {1st and last A in the same house} loop
Cycle                                          {includes 222 swordfish}

X-Cycle:    A  =  A  -  A  =  A  -  A  =   A   {1st and last A not in the same house}


W-Wing:      (A=B)   -  B  =  B  -   (B=A)

gM-Wing:     (A=B)   -  B  =   (B-A)   =   A

S-Wing:     A  =  A  -   (A=B)   -  B  =   B   {1st A and last B in the same house}

unnamed:    A  =  A  -  A  = (A  -  B) =   B   {1st A and last B in the same house}
(reverse)   B  = (B  -  A) =  A  -  A  =   A   {1st B and last A in the same house}


XY-Wing:     (A=B)   -   (B=C)   -   (C=A)

inv/XY:     A  =   (A-B)   =   (B-C)   =   C   {1st A and last C are in the same house}

If you examine the table above, you'll notice there are four entries with only two candidate values present. Norm once referred to the S-Wing as a "Cyclops", but it was essentially unnamed until S-Wing came along. That leaves one unnamed entry, and I'm calling it E-Turbot. The first 2-SIS represent a turbot fish pattern that'd provide eliminations for the single digit A. However, the 2-SIS can be extended into the fifth cell of the turbot pattern through a strong link on a second candidate value -- thus the E part of the name on this 3-SIS.

Besides the M-Wing and S-Wing mentioned by Peter for this puzzle, there's also an E-Turbot present:

Code:
 E-Turbot: 4C1 4C8 8R9 : (4)r8c1 = r5c1 - r5c8 = (4-8)r9c8 = (8)r9c3  =>  r9c3<>4, r8c1<>8
 +--------------------------------------------------------------+
 |  7     2     18    |  4     59    159   |  3     89    6     |
 |  5     9     3     |  8     7     6     |  4     1     2     |
 |  18    4     6     |  2     3     19    |  5     7     89    |
 |--------------------+--------------------+--------------------|
 |  9     3     2     |  5     1     4     |  8     6     7     |
 | *14    8     5     |  6     2     7     |  19   *49    3     |
 |  6     7     14    |  39    8     39    |  2     5     14    |
 |--------------------+--------------------+--------------------|
 |  2     5     7     |  1     49    89    |  6     3     489   |
 | *48    16    489   |  39    4569  3589  |  7     2     1489  |
 |  3     16   @489   |  7     469   2     |  19  @*489   5     |
 +--------------------------------------------------------------+
 # 41 eliminations remain
__________________________________________________________________________________________

For those with a good memory, you'll recall that I mentioned this pattern awhile back in
Atypical Extension of Non-Productive Skyscraper.


Last edited by daj95376 on Tue Sep 21, 2010 8:09 pm; edited 2 times in total
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ronk



Joined: 07 May 2006
Posts: 398

PostPosted: Tue Sep 21, 2010 7:57 pm    Post subject: Reply with quote

daj95376 wrote:
That leaves one unnamed entry, and I'm calling it XY-Turbot. The first 2-SIS represent a turbot fish pattern that'd provide eliminations for the single digit A. However, the 2-SIS can be extended into the fifth cell of the turbot pattern through a strong link on a second candidate value -- thus the XY part of the name on this 3-SIS.

Let's see now. In an xy-wing, 100% of the strong inferences are bivalued cells. In an xy-chain, 100% of the strong inferences are bivalued cells.

Using your proposed name, we would have an xy-turbot without even one bivalued cell. Consequently, that name seems ill-advised.
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Tue Sep 21, 2010 8:11 pm    Post subject: Reply with quote

Ron, you slipped in right in the middle of my coming to the same conclusion. What do you think of the updated name?
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK

PostPosted: Tue Sep 21, 2010 8:52 pm    Post subject: Reply with quote

I don't know but for me "turbot" says single digit only - whereas "wing" says two digits. "t-wing" for turbot wing?

btw I have seen mention of h-wings - but never a clear definition?
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Wed Sep 22, 2010 12:41 am    Post subject: Reply with quote

Coloring (4) + two extensions
XYZ-Wing (189)
Multi-coloring (9)
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ronk



Joined: 07 May 2006
Posts: 398

PostPosted: Mon Sep 27, 2010 12:47 pm    Post subject: Reply with quote

daj95376 wrote:
Ron, you slipped in right in the middle of my coming to the same conclusion. What do you think of the updated name?

As you might guess, I'm reluctant to put names on too many patterns. If this one must be named, however, I suggest "L-Wing." The "wing" because there are 3 strong links and the "L" because the strong links are 100% biLocaLs. One can take this a step further and have an "L2-Wing" and an "L3-wing" for 2 and 3 digits, respectively.

Using your nomenclature:

L2-Wing: A = (A - B) = B - B = B

L3-Wing: A = (A - B) = (B - C) = C
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Mon Sep 27, 2010 5:22 pm    Post subject: Reply with quote

ronk wrote:
I'm reluctant to put names on too many patterns.

If this one must be named, however, I suggest "L-Wing." The "wing" because there are 3 strong links and the "L" because the strong links are 100% biLocaLs. One can take this a step further and have an "L2-Wing" and an "L3-wing" for 2 and 3 digits, respectively.

Using your nomenclature:

L2-Wing: A = (A - B) = B - B = B

L3-Wing: A = (A - B) = (B - C) = C

I understand your reluctance and agree that every pattern does not need a name. Since it's the only unnamed pattern (that I believe remains) in my "3:2 group", It seems awkward not to give it a name. I can accept "L-Wing". I hope others find it acceptable as well. Thanks!

Regards, Danny
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