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Puzzle 10/09/07: D

 
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Tue Sep 07, 2010 12:32 am    Post subject: Puzzle 10/09/07: D Reply with quote

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

Play this puzzle online at the Daily Sudoku site


generic Solution wrote:
<27> UR Type 1 (extraneous)
<5> Sashimi X-Wing
<25+4> XY-Wing (extraneous)
either of 2x 5-cell XY-Chain

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Mogulmeister



Joined: 03 May 2007
Posts: 703

PostPosted: Tue Sep 07, 2010 3:44 am    Post subject: Reply with quote

There's an almost RP(25) configuration (*) with the fin being the 9 in r1c3:

If RP(25) true then r5c3<>5
If fin true then (25=9)r1c3-(9=5)r7c3 and r5c3<>5





Code:
+-------------------+-------------------+-------------------+
| 6     4579  *25+9 | 8     3     *25   | 24    1     57    |
| 578   3457  235   | 2457  1     6     | 248   9     57    |
| 578   457   1     | 2457  27    9     | 248   6     3     |
+-------------------+-------------------+-------------------+
| 4     *25   8     | 1     9     *25   | 3     7     6     |
| 17    17    3-5   | 35    6     4     | 9     8     2     |
| 9     23    6     | 23    8     7     | 5     4     1     |
+-------------------+-------------------+-------------------+
| 15    159   59    | 27    27    8     | 6     3     4     |
| 2     8     7     | 6     4     3     | 1     5     9     |
| 3     6     4     | 9     5     1     | 7     2     8     |
+-------------------+-------------------+-------------------+
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JC Van Hay



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

PostPosted: Tue Sep 07, 2010 5:17 am    Post subject: Reply with quote

Quote:
5-SIS AIC : (M Wing) [2C3 3C2 (32)R6C2 2B5] (25)R1C6
:::::::::::: : (2)r1c3=(5)r1c6 : => r1c3<>5, r1c6<>2

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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Tue Sep 07, 2010 7:17 am    Post subject: Reply with quote

JC Van Hay wrote:
5-SIS AIC : (M Wing) [2C3 3R2 (32)R6C2 2B5] (25)R1C6
:::::::::::: : (2)r1c3=(5)r1c6 : => r1c3<>5, r1c6<>2

JC: Although your solution is correct, this is the third time recently that you've labeled your AIC as (containing?) an "M-Wing" ... and I have no idea how you came to that conclusion.

Most of us are using the (generalized) version of Keith's definition posted here.

gM-Wing: (Y=X)a - (X)b = (X-Y)r = (Y)s => eliminations for (Y) in peers common to [a] and [s]

How are you getting an M-Wing from your AIC?

Regards, Danny
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JC Van Hay



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

PostPosted: Tue Sep 07, 2010 10:19 am    Post subject: Reply with quote

Danny, I am certainly confused about the namings.
    After SSTS and a useless AIC, I noticed that the most promising digits for AICs are 2, 3 and 5 (lot of strengths in location). I therefore first looked for cells containing 2 and 3 and tried an AIC from them. The obtained AIC contains a remote hidden pair (23). That's why I called the AIC snippet containing them "M Wing" even if it doesn't lead directly to an elimination :
      (M Wing)[(23)R6C2 3R2 2C3] or (2=3)r6c2-r2c2=(3-2)r2c3=r1c3, to model to your recalled notation.
    I should therefore have written (M Wing) [2C3 3R2 (32)R6C2] 2B5 (25)R1C6 instead.

    Calling an AIC an M Wing AIC is thus a way to draw the attention to a contained M Wing snippet. To prevent confusion, I think that AIC with M Wing would be more clear, as in AIC with groups or ALS. I also, may be wrongfully, extended the naming "M Wing" to any AIC snippet on 2 digits only! Thus the posted notation.

    In the same line of thought, I generally prefer to call a 3-SIS AIC an XY Wing Style instead of H, (g)M, S, W, Y ... Wings, apart from the reserved names, Naked and Hidden Triples, XY(Z) Wings.

    To give an example of such a stretched naming, I had in the same puzzle, from the "hub" cell R1C2 with 3 spokes :
      "M Wing" XY Wing Style, 9R1 as pivot : 7R1 9R1 (M Wing)[(95)R7C3 5R5 5C6] : (7)r1c9=(5)r1c6 : => r1c9<>5, only 2 singles
    which sounds less dry than 5-SIS AIC ! Even if the M Wing snippet is not a true M Wing one. This is just "similar" to ALS XY Wing (Style).
Final comment : after re-reading Keith's post, I think that the idea I wanted to convey seems similar to the Extended XY Wing (Style) (to take with a grain of salt ...).

Regards, JC
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peterj



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

PostPosted: Tue Sep 07, 2010 4:38 pm    Post subject: Reply with quote

daj95376 wrote:
How are you getting an M-Wing from your AIC?


My interpretation of JCs move would be an m-wing(23) with pseudocell
Code:
(X       =       Y)  - Y   =(Y-X)   =   X
(2=5)r4c6-(5=3)r5c4 - r5c3=(3-2)r2c3=r1c3 ; r1c6<>2


Whether that's a correct interpretation of his SIS I am not sure as it only has 4 strong links and JC stated a 5-SIS - but it's how I have been presenting similar moves.
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Tue Sep 07, 2010 5:12 pm    Post subject: Reply with quote

JC Van Hay wrote:
Danny, I am certainly confused about the namings.
    After SSTS and a useless AIC, I noticed that the most promising digits for AICs are 2, 3 and 5 (lot of strengths in location). I therefore first looked for cells containing 2 and 3 and tried an AIC from them. The obtained AIC contains a remote hidden pair (23). That's why I called the AIC snippet containing them "M Wing" even if it doesn't lead directly to an elimination :
      (M Wing)[(23)R6C2 3R2 2C3] or (2=3)r6c2-r2c2=(3-2)r2c3=r1c3, to model to your recalled notation.
    I should therefore have written (M Wing) [2C3 3R2 (32)R6C2] 2B5 (25)R1C6 instead.

    Calling an AIC an M Wing AIC is thus a way to draw the attention to a contained M Wing snippet. To prevent confusion, I think that AIC with M Wing would be more clear, as in AIC with groups or ALS. I also, may be wrongfully, extended the naming "M Wing" to any AIC snippet on 2 digits only! Thus the posted notation.

    In the same line of thought, I generally prefer to call a 3-SIS AIC an XY Wing Style instead of H, (g)M, S, W, Y ... Wings, apart from the reserved names, Naked and Hidden Triples, XY(Z) Wings.

    To give an example of such a stretched naming, I had in the same puzzle, from the "hub" cell R1C2 with 3 spokes :
      "M Wing" XY Wing Style, 9R1 as pivot : 7R1 9R1 (M Wing)[(95)R7C3 5R5 5C6] : (7)r1c9=(5)r1c6 : => r1c9<>5, only 2 singles
    which sounds less dry than 5-SIS AIC ! Even if the M Wing snippet is not a true M Wing one. This is just "similar" to ALS XY Wing (Style).
Final comment : after re-reading Keith's post, I think that the idea I wanted to convey seems similar to the Extended XY Wing (Style) (to take with a grain of salt ...).

Thanks JC for the detailed explanation.

I'm locked into a gM-Wing being directional from a bivalue cell. I was just tired enough last night to miss the reverse direction on your flightless M-Wing. I probably would have caught it if you'd written your AIC in the reverse direction:

5-SIS AIC : (52)R1C6 2B5 (M-Wing) [(23)R6C2 3R2 2C3] : (5)r1c6=(2)r1c3 : => r1c3<>5, r1c6<>2

BTW: I like the endpoint synopsis being included in the conclusion.

Thanks also for explaining your use of "XY Wing Style". However, I'll hold off agreeing with your statement, Even if the M-Wing snippet is not a true M-Wing one. At some point, a 3-SIS is just a 3-SIS and nothing more!

Next time, I'll check the reverse direction of your AIC with both eyes open. _ Smile _

Regards, Danny



Peter: Thanks for trying to help, but I believe you are using the wrong cells.

Code:
 +--------------------------------------------------------------+
 |  6     4579 a259   |  8     3    g25    |  24    1     57    |
 |  578  c3457 b235   |  2457  1     6     |  248   9     57    |
 |  578   457   1     |  2457  27    9     |  248   6     3     |
 |--------------------+--------------------+--------------------|
 |  4     25    8     |  1     9    f25    |  3     7     6     |
 |  17    17    35    |  35    6     4     |  9     8     2     |
 |  9    d23    6     | e23    8     7     |  5     4     1     |
 |--------------------+--------------------+--------------------|
 |  15    159   59    |  27    27    8     |  6     3     4     |
 |  2     8     7     |  6     4     3     |  1     5     9     |
 |  3     6     4     |  9     5     1     |  7     2     8     |
 +--------------------------------------------------------------+
 # 45 eliminations remain

    2C3           3R2        (32)R6C2        2B5       (25)R1C6
************ *************   *********   ***********   *********
(2)r1c3 = (2-3)r2c3 = r2c2 - (3=2)r6c2 - r6c4 = r4c6 - (2=5)r1c6
|<-----------------------------------|

The first 3-SIS (four cells) in JC's AIC are a flightless M-Wing reading from right-to-left.
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peterj



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

PostPosted: Tue Sep 07, 2010 5:20 pm    Post subject: Reply with quote

daj95376 wrote:
Peter: Thanks for trying to help, but I believe you are using the wrong cells..

Sorry Embarassed I'll stick with my m-wing solution then!
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Mogulmeister



Joined: 03 May 2007
Posts: 703

PostPosted: Tue Sep 07, 2010 9:13 pm    Post subject: Reply with quote

After muich prodding about, another AIC - all around 2s and 3s:

(457-3)r2c2=r6c2-(3=2)r6c4-r4c6=r1c6-r1c3=(2-3)r2c3=(3)r2c2; r2c2=3
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Marty R.



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

PostPosted: Wed Sep 08, 2010 3:37 pm    Post subject: Reply with quote

Coloring (5)
XY-Wing (295), flightless with pincer transport
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