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Puzzle 10/08/03: C

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Tue Aug 03, 2010 4:23 pm    Post subject: Puzzle 10/08/03: C Reply with quote

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

Play this puzzle online at the Daily Sudoku site

Rating wrote:
XY
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Mogulmeister



Joined: 03 May 2007
Posts: 1151

PostPosted: Tue Aug 03, 2010 5:16 pm    Post subject: Reply with quote

ALS xz

A={2,4,6}
B={2,4,7,8,9}
x= 2; linked at r47c2
z= 4; r4c9<>4

Code:
+----------------------+----------------------+----------------------+
| 7      3      89     | 456    459    2      | 689    1      5689   |
| 2      5      1      | 67     379    8      | 679    4      3679   |
| 489    48     6      | 57     3579   1      | 2      357    35789  |
+----------------------+----------------------+----------------------+
| A46   A26     23     | 9      1      7      | 5      8      3-4    |
| 1      48     38     | 2      6      5      | 479    37     3479   |
| 5      9      7      | 3      8      4      | 1      6      2      |
+----------------------+----------------------+----------------------+
| B89    B27    5      | 1      247    6      | 3     B79    B48     |
| 3      1      4      | 8      57     9      | 67     2      567    |
| 689    267    289    | 457    2457   3      | 48     579    1      |
+----------------------+----------------------+----------------------+


I saw the ALS first before I noticed it was also a real xx XY chain with pincers at r4c1 & r7c9
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JC Van Hay



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

PostPosted: Tue Aug 03, 2010 7:51 pm    Post subject: Reply with quote

4-SIS AIC : 2R7 4R7 4R4 6R4 => r4c2<>2
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peterj



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

PostPosted: Tue Aug 03, 2010 8:31 pm    Post subject: Reply with quote

Mm, nice ALS-XZ - I'm still some way off naturally spotting those!

This grid has a lot of xy options - especially xy-chains in r4 and r7.
I was looking for m-wings, here's one with a pseudo-cell at the front - I am sure there are more!

Code:
m-wing(24) (2=3)r4c3-(3=4)r4c9 - r7c9=(4-2)r7c5=r7c2;  r4c2<>2, r9c3<>2
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Marty R.



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

PostPosted: Thu Aug 05, 2010 4:32 am    Post subject: Reply with quote

ER (5)
Potential DP (45) in boxes 28; all DP killers lead to r79c8=95.
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ronk



Joined: 07 May 2006
Posts: 398

PostPosted: Thu Aug 05, 2010 6:48 pm    Post subject: Reply with quote

Marty R. wrote:
ER (5)
Potential DP (45) in boxes 28; all DP killers lead to r79c8=95.

I don't think I'm seeing the same results from that AUR; mine is r9c5<>5. Would you please elaborate?
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Marty R.



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

PostPosted: Thu Aug 05, 2010 9:32 pm    Post subject: Reply with quote

ronk wrote:
Marty R. wrote:
ER (5)
Potential DP (45) in boxes 28; all DP killers lead to r79c8=95.

I don't think I'm seeing the same results from that AUR; mine is r9c5<>5. Would you please elaborate?

R9c5 being<>5 is certainly compatible with my r9c8 being=5.
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Marty R.



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

PostPosted: Thu Aug 05, 2010 10:27 pm    Post subject: Reply with quote

However, to further elaborate, this is my grid after an ER on 5:

Code:

+-------------+------------+---------------+
| 7   3   89  | 456 459  2 | 689 1   5689  |
| 2   5   1   | 67  379  8 | 679 4   3679  |
| 489 48  6   | 57  379  1 | 2   357 35789 |
+-------------+------------+---------------+
| 46  26  23  | 9   1    7 | 5   8   34    |
| 1   48  38  | 2   6    5 | 479 37  3479  |
| 5   9   7   | 3   8    4 | 1   6   2     |
+-------------+------------+---------------+
| 89  27  5   | 1   247  6 | 3   79  48    |
| 3   1   4   | 8   57   9 | 67  2   567   |
| 689 267 289 | 457 2457 3 | 48  579 1     |
+-------------+------------+---------------+

Play this puzzle online at the Daily Sudoku site

The DP killers are:

1) 3679 pseudo cell in box 2
2) R9c4 or r9c5=7
3) R9c5=2

All three lead to r79c8=95. I could've also said all three lead to r7c9 and r9c7=48 or r7c1=8 or r8c5=5 or, as you mentioned, r9c5<>5.
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Thu Aug 05, 2010 11:03 pm    Post subject: Reply with quote

In a Ruud thread that was lost during the crash of the Players' Forums, I once asked (paraphrased), "What restrictions apply to what can be done to resolve a UR pattern." His reply (paraphrased), "None."

Marty, congratulations on taking Ruud's reply to the limit!!!

Code:
 *--------------------------------------------------------------------*
 | 7      3      89     | 45+6   45+9   2      | 689    1      5689   |
 | 2      5      1      | 67     379    8      | 679    4      3679   |
 | 489    48     6      | 57     379    1      | 2      357    35789  |
 |----------------------+----------------------+----------------------|
 | 46     26     23     | 9      1      7      | 5      8      34     |
 | 1      48     38     | 2      6      5      | 479    37     3479   |
 | 5      9      7      | 3      8      4      | 1      6      2      |
 |----------------------+----------------------+----------------------|
 | 89     27     5      | 1      247    6      | 3      79     48     |
 | 3      1      4      | 8      57     9      | 67     2      567    |
 | 689    267    289    | 45+7   45+27  3      | 48     579    1      |
 *--------------------------------------------------------------------*

Code:
(6)r1c4 - (6=89=5)r1c379 - (5)r8c7  = (5-9)r9c8 = (9)r7c8

(9)r1c5 - (9=68=5)r1c379 - (5)r8c7  = (5-9)r9c8 = (9)r7c8

(7)r7c45 - (7=5)8c5      - (5)r9c45 = (5-9)r9c8 = (9)r7c8

(2)r9c5 - r7c5 = r7c2 - r4c3 = (2-3)r4c3 = r5c3 - (3=7)r5c8 - (7=9)r7c8 - (79=5)r9c8

In every instance, r7c8=9 and r9c8=5 !!!
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Marty R.



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

PostPosted: Fri Aug 06, 2010 12:22 am    Post subject: Reply with quote

Quote:
Marty, congratulations on taking Ruud's reply to the limit!!!

Thanks Danny. I use those URs like that fairly frequently, although it's far from my favorite technique. But, as they say, "ya do what ya gotta do."
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ronk



Joined: 07 May 2006
Posts: 398

PostPosted: Fri Aug 06, 2010 1:13 am    Post subject: Reply with quote

Marty R. & daj95376, now that you've shown the way, here's a somewhat simpler POV using candidates external to the AUR. At least one of DP busters r9c8=5, r3c4=5 and r7c5=4 must ultimately be true.

Code:
(5)r9c8
 ||
(5)r3c4 - (5)r3c89 = (5)r13c9 - (5)r8c9 = (5)r9c8
 ||
(4-2)r7c5 = (2)r7c2 - (2)r4c2 = (2-3)r4c3 = (3)r5c3 - (3=79)als:r57c8 - (79=5)aals:r9c8 => r9c8=5

Marty R., that's a bit complicated but still very nice.


Last edited by ronk on Fri Aug 06, 2010 7:14 am; edited 1 time in total
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Mogulmeister



Joined: 03 May 2007
Posts: 1151

PostPosted: Fri Aug 06, 2010 6:37 am    Post subject: Reply with quote

[Fixed!]
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Thu Aug 12, 2010 6:57 pm    Post subject: Reply with quote

Another one step solution..............

ANP(89=2)r19c3-r9c5=(2-4)r7c5=r7c9-(4=3)r4c9-r4c3=(3)r5c3; r5c3<>8

Ted
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