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Might be tricky!

 
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Thu Feb 03, 2011 6:01 pm    Post subject: Might be tricky! Reply with quote
Code:
Puzzle: M6675091sh(22)
+-------+-------+-------+
| . . 7 | . . . | 8 . . |
| 9 8 . | 7 . 6 | . 3 2 |
| . 6 . | . 9 8 | . 7 . |
+-------+-------+-------+
| . . . | 6 . . | 2 4 . |
| 5 . . | . . . | . . 1 |
| . 2 9 | . . 4 | . . . |
+-------+-------+-------+
| . 9 . | . 3 7 | . 1 . |
| 1 3 . | 5 . 9 | . 6 8 |
| . . 5 | . . . | 9 . . |
+-------+-------+-------+

Keith
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Thu Feb 03, 2011 8:29 pm    Post subject: Reply with quote
Ignoring the reason I posted this puzzle ...

After basics:
Code:
+----------------+----------------+----------------+
| 234  5    7    | 1234 124  23   | 8    9    6    |
| 9    8    14   | 7    5    6    | 14   3    2    |
| 234  6    1234 | 234  9    8    | 145  7    45   |
+----------------+----------------+----------------+
|37-8  1    38d  | 6    78   5    | 2    4    9    |
| 5    47   46   | 9    27   23   | 36   8    1    |
| 68a  2    9    | 13   18   4    | 36   5    7    |
+----------------+----------------+----------------+
| 268b 9    268c | 28   3    7    | 45   1    45   |
| 1    3    24   | 5    24   9    | 7    6    8    |
| 478  47   5    | 48   6    1    | 9    2    3    |
+----------------+----------------+----------------+

Quote:
abcd is a nice M-wing.

That opens up a flightless XY-wing -368 which, with pincer transport, takes out 3 in R6C4.

A satisfying two step solution.

Keith
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Thu Feb 03, 2011 10:47 pm    Post subject: Reply with quote
keith wrote:
Ignoring the reason I posted this puzzle ...

Too bad. I think there is an interesting/challenging alternate solution.
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Thu Feb 03, 2011 10:48 pm    Post subject: Reply with quote
Another interesting two-step...
Code:
 *-----------------------------------------------------------*
 | 234   5     7     | 1234  124   23    | 8     9     6     |
 | 9     8    *14    | 7     5     6     |*14    3     2     |
 | 234   6    *14+23 | 234   9     8     |*145   7    *45    |
 |-------------------+-------------------+-------------------|
 | 378   1     38    | 6     78    5     | 2     4     9     |
 | 5     47    46    | 9     27    23    | 36    8     1     |
 | 68    2     9     | 13    18    4     | 36    5     7     |
 |-------------------+-------------------+-------------------|
 | 268   9     268   | 28    3     7     |*45    1    *45    |
 | 1     3     24    | 5     24    9     | 7     6     8     |
 | 478   47    5     | 48    6     1     | 9     2     3     |
 *-----------------------------------------------------------*

Overlapping UR(45) and UR(14) make a Type-1 MUG. If you play the obvious Type-1 UR(45) it is very easy to miss the Avoidable Rectangle(14)...
Code:
MUG(145) ; r3c3<>14
w-wing(78) ; (7=8)r4c5 - r6c5=6c1 - (8=7)r9c1 ; r4c1<>7
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Thu Feb 03, 2011 11:03 pm    Post subject: Reply with quote
daj95376 wrote:
keith wrote:
Ignoring the reason I posted this puzzle ...

Too bad. I think there is an interesting/challenging alternate solution.

... which is the reason I posted the puzzle!

Most, I think, would find one or other or the UR's 14, 45. If you find only one, it is a hard road. If you find both and make the eliminations together, there is just an XYZ-wing to complete the puzzle.

To be more specific: The 14 UR takes out 4 in R3C3 and R3C7. The 45 UR solves R3C7 as 1. Either UR destroys the other.

(But, I really do like that M-wing!)

Keith
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Thu Feb 03, 2011 11:10 pm    Post subject: Reply with quote
keith wrote:
(But, I really do like that M-wing!)

FWIW I think you can "upgrade" it to an m-ring! And so eliminate (2)r7c3 - it doesn't change the solution path...
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Thu Feb 03, 2011 11:28 pm    Post subject: Reply with quote
peterj wrote:
keith wrote:
(But, I really do like that M-wing!)

FWIW I think you can "upgrade" it to an m-ring! And so eliminate (2)r7c3 - it doesn't change the solution path...

Peter, I was just thinking about that ... the pincers are in the same house ...

Keith
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royalina



Joined: 21 Feb 2011
Posts: 4
PostPosted: Mon Feb 21, 2011 6:49 am    Post subject: Reply with quote
If you find both and make the eliminations together, there is just an XYZ-wing to complete the puzzle. 。
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