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My kind of puzzle

 
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Thu Oct 30, 2008 1:10 am    Post subject: My kind of puzzle Reply with quote

Not yet finished ...
Code:
Puzzle: M5668611sh(25)
+-------+-------+-------+
| . . 9 | . . 6 | 5 . . |
| 5 . . | 7 . . | . . 1 |
| 3 . 4 | . . 5 | 2 . 6 |
+-------+-------+-------+
| 7 . . | 6 5 . | . . 9 |
| . 4 . | . 9 . | . 6 . |
| . . . | . 8 7 | . . . |
+-------+-------+-------+
| 4 . 6 | . . 9 | 3 . 8 |
| 8 . . | 1 . . | . . 4 |
| . . 7 | . . 8 | 6 . . |
+-------+-------+-------+

Keith
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Thu Oct 30, 2008 3:44 am    Post subject: Reply with quote

Here's a path I found. Perhaps someone can find a more efficient solution.

[1] Finned X-Wing c49: r9c5<>2
[2] 78 W-Wing c78: r2c7|r4c8<>8
[3] Finned X-Wing c67: r4c8<>4
[4] 234 XY Wing: r2c8<>3

That gets us here:
Code:
+-------------+-----------------+----------------+
| 1  2r7  9   | 8   2g4    6    | 5    347   37  |
| 5  6    2g8 | 7   2r3r4  3g4  | 49   489   1   |
| 3  78   4   | 9   1      5    | 2    78    6   |
+-------------+-----------------+----------------+
| 7  38   138 | 6   5      24   | 148  23    9   |
| 2  4    58  | 3   9      1    | 78   6     57  |
| 6  9    135 | 24  8      7    | 14   2345  235 |
+-------------+-----------------+----------------+
| 4  12   6   | 25  7      9    | 3    125   8   |
| 8  5    2r3 | 1   6      2g3r | 79   79    4   |
| 9  123  7   | 245 34     8    | 6    125   25  |
+-------------+-----------------+----------------+

[5] Medusa Wrap, as marked: r2c5=4.
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Thu Oct 30, 2008 4:15 am    Post subject: Reply with quote

Basics, to here:
Code:
+----------------+----------------+----------------+
| 1    27   9    | 8    234  6    | 5    347  37   |
| 5    6    28   | 7    234  234  | 489  3489 1    |
| 3    78   4    | 9    1    5    | 2    78   6    |
+----------------+----------------+----------------+
| 7    38   138  | 6    5    24   | 148  2348 9    |
| 2    4    58   | 3    9    1    | 78   6    57   |
| 6    9    135  | 24   8    7    | 14   2345 235  |
+----------------+----------------+----------------+
| 4    12   6    | 25   7    9    | 3    125  8    |
| 8    5    23   | 1    6    23   | 79   79   4    |
| 9    123  7    | 245  234  8    | 6    125  25   |
+----------------+----------------+----------------+

Type 6 UR takes out <2> in R9C8. Probably irrelevant.

W-wing <78> takes out <8> in R4C8.

Extended half M-wing <38> in R4C2 and <78> in R5C7 takes out <8> in R4C7.

Leading to here:
Code:
+-------------+-------------+-------------+
| 1   27  9   | 8   24  6   | 5   47  3   |
| 5   6   28  | 7   234 234 | 9   48  1   |
| 3   78  4   | 9   1   5   | 2   78  6   |
+-------------+-------------+-------------+
| 7   38  138 | 6   5   24  | 14  23  9   |
| 2   4   5   | 3   9   1   | 8   6   7   |
| 6   9   13  | 24  8   7   | 14  235 25  |
+-------------+-------------+-------------+
| 4   12  6   | 25  7   9   | 3   125 8   |
| 8   5   23  | 1   6   23  | 7   9   4   |
| 9   123 7   | 245 234 8   | 6   15  25  |
+-------------+-------------+-------------+

Which seems to be more resolved than Asellus' position. Do we need Medusa?

Keith
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Marty R.



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

PostPosted: Thu Oct 30, 2008 4:53 am    Post subject: Reply with quote

W-Wing 78
ER 4
Hidden UR 12
Finned X-Wing 2
XY-Wing 243
XY-Wing 342 with pincer coloring

My final step appears in Asellus' grid with pivot in r2c6, knocking out the 2 from r8c3.
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Thu Oct 30, 2008 7:22 am    Post subject: Reply with quote

[Replaced]

Code:
finned X-Wing c49\r69                        =>  [r9c5]<>2
finned X-Wing c67\r24                        =>  [r4c8]<>4

W-Wing        [r3c8] sl(7:c9) [r5c7]         =>  [r2c7],[r4c8]<>8

XY-Wing       [r4c6]/[r2c6]+[r4c8]           =>  [r2c8]<>3

Half M-Wing   [r8c3] sl(2:r2) [r2c5] [r9c5]  =>  [r8c6],[r9c2]<>3


Last edited by daj95376 on Thu Oct 30, 2008 2:29 pm; edited 1 time in total
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nataraj



Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria

PostPosted: Thu Oct 30, 2008 7:37 am    Post subject: Reply with quote

Starting with coloring, I found (not too helpful)

Kite (4) row 1, col 6: r4c8<>4
multi-coloring (2): r9c2<>2 (this one goes all around the board)

w-wing (8)r3c8=r5c7

Code:

+--------------------------+--------------------------+--------------------------+
| 1       27      9        | 8       234     6        | 5       347     37       |
| 5       6       28+      | 7       234     234      | 4-89    3489    1        |
| 3       78+     4        | 9       1       5        | 2       78*     6        |
+--------------------------+--------------------------+--------------------------+
| 7       38      138      | 6       5       24       | 148     23-8    9        |
| 2       4      5-8       | 3       9       1        | 78*     6       57       |
| 6       9       135      | 24      8       7        | 14      2345    235      |
+--------------------------+--------------------------+--------------------------+
| 4       12      6        | 25      7       9        | 3       125     8        |
| 8       5       23       | 1       6       23       | 79      79      4        |
| 9       13      7        | 245     234     8        | 6       125     25       |
+--------------------------+--------------------------+--------------------------+


This w-wing is quite interesting, since it not only eliminates 8 from r2c7 and r4c8 (the two cells that directly see the ends of the w-wing)

but ALSO r5c3<>8 !!! (transport via sl in box 1)

The (25) UR inr69c89 /w sl (5) in row 6 makes r9c8<>2.

Now turning to candidate "2":

there is a "useless" w-wing here: (in fact, several w-wings)

Code:


+--------------------------+--------------------------+--------------------------+
| 1       27      9        | 8       24      6        | 5       47      3        |
| 5       6       28       | 7       234     234      | 9       48      1        |
| 3       78      4        | 9       1       5        | 2       78      6        |
+--------------------------+--------------------------+--------------------------+
| 7       38      138      | 6       5       24       | 14      23      9        |
| 2       4       5        | 3       9       1        | 8       6       7        |
| 6       9       13       | 24      8       7        | 14      235     25       |
+--------------------------+--------------------------+--------------------------+
| 4       12      6        | 25      7       9        | 3       125     8        |
| 8       5       23       | 1       6       23       | 7       9       4        |
| 9       13      7        | 245     234     8        | 6       15      25       |
+--------------------------+--------------------------+--------------------------+


w-wing (2):r1c5,r6c4 (via sl (4) in row 9)
and (2):r4c8,r8c3 (via sl (3) col 2)

Add these 2 strong links to the existing web of strong links in (2) - or, in other words: "transport them" -and there are so many eliminations that the puzzle falls apart (I lost track which one actually solved the puzzle)
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cgordon



Joined: 04 May 2007
Posts: 769
Location: ontario, canada

PostPosted: Thu Oct 30, 2008 1:48 pm    Post subject: Reply with quote

Can you have a double-edged ER?

In the grid below (for this puzzle) There are only two <2>s in R4
If I choose the left one, I can go UP to the hinge in Box2 and DOWN to eliminate R9C5.
If I choose the right one I can use the hinge in Box9 to make the same elimination.

This leads to the elimination of <2> in R2C6 which doesn't seem to help this puzzle. But that ain't the point!

I come across these from time to time. Asellus once told me
about ER’s with transported pincers but this looks different.


Code:
            
+-------+-------+-------+   
| . . . | . 2 . | . . . |   
| . . . | . 2 2 | . . . |   
| . . . | . . . | . . . |   
+-------+-------+-------+   
| . . . | . . 2 | . 2 . |   
| . . . | . . . | . . . |   
| . . . | 2 . . | . 2 2 |   
+-------+-------+-------+   
| . . . | . . . | . 2 . |   
| . . . | . . . | . 2 . |   
| . . . | . 2 . | . 2 2 |
+-------+-------+-------+
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daj95376



Joined: 23 Aug 2008
Posts: 3854

PostPosted: Thu Oct 30, 2008 2:58 pm    Post subject: Reply with quote

cgordon wrote:
Can you have a double-edged ER?

Hello Craig. Your double-edged ER works for [r9c5]<>2. (Every elimination is important in this puzzle -- even [r2c6]<>2.)

Here's an alternate way, using sl(2:c9), to get your first elimination.

Code:
 [r9c9]=2                           => [r9c5]<>2
 [r6c9]=2 => [r6c4]<>2 => [r79c4]=2 => [r9c5]<>2
 +-----------------------------------+
 |  .  2  .  |  .  2  .  |  .  .  .  |
 |  .  .  2  |  .  2  2  |  .  .  .  |
 |  .  .  .  |  .  .  .  |  2  .  .  |
 |-----------+-----------+-----------|
 |  .  .  .  |  .  .  2  |  .  2  .  |
 |  2  .  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  | *2  .  .  |  .  2 *2  |
 |-----------+-----------+-----------|
 |  .  2  .  | #2  .  .  |  .  2  .  |
 |  .  .  2  |  .  .  2  |  .  .  .  |
 |  .  2  .  | *2 -2  .  |  .  2 *2  |
 +-----------------------------------+

These cells also represent a finned X-Wing. If the fin cell (#) is true, then [r9c5]<>2; otherwise, the X-Wing (*) is true and [r9c5]<>2 as well.

There's an important finned X-Wing for (4) as well.

Code:
 +-----------------------------------+
 |  .  .  .  |  .  4  .  |  .  4  .  |
 |  .  .  .  |  .  4  4  |  4  4  .  |
 |  .  .  4  |  .  .  .  |  .  .  .  |
 |-----------+-----------+-----------|
 |  .  .  .  |  .  .  4  |  4  4  .  |
 |  .  4  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  |  4  .  .  |  4  4  .  |
 |-----------+-----------+-----------|
 |  4  .  .  |  .  .  .  |  .  .  .  |
 |  .  .  .  |  .  .  .  |  .  .  4  |
 |  .  .  .  |  4  4  .  |  .  .  .  |
 +-----------------------------------+
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Thu Oct 30, 2008 7:54 pm    Post subject: Reply with quote

I like Marty's solution.

I found the same accidentally, when looking for UR's. Pure t&e of course, but i dont care Smile
Code:

 *-----------------------------------------------------------*
 | 1    >27    9     | 8    *24    6     | 5     347   37    |
 | 5     6    >28    | 7     234  *34    | 49    489   1     |
 | 3     78    4     | 9     1     5     | 2     78    6     |
 |-------------------+-------------------+-------------------|
 | 7     38    138   | 6     5     24    | 148   23    9     |
 | 2     4     58    | 3     9     1     | 78    6     57    |
 | 6     9     135   | 24    8     7     | 14    2345  235   |
 |-------------------+-------------------+-------------------|
 | 4    #12    6     | 25    7     9     | 3    #125   8     |
 | 8     5    @23    | 1     6    *23    | 79    79    4     |
 | 9    #123   7     | 245   34    8     | 6    #125  @25    |
 *-----------------------------------------------------------*

From the UR 12 (r79c28) with the 1-x-wing you get directly r9c8<>2.
Looking at the boxes r8c3=2 or r9c9=2, r9c2<>2.
No help so far, also transporting r8c3 to r1c2, r2c5 or r4c6 did not lead to further eliminations.
But using the bivalue cells i got r8c3=2 => r8c6=3 => r2c6=4 => r1c5=2
Oops, not both r1c2 and r1c5 can be 2, so r8c3<>2.

So the UR was not needed at all, but was my way to find it.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Thu Oct 30, 2008 8:37 pm    Post subject: Reply with quote

the 7 in r1c8 is all that stands in the way of a one stepper that joins two useless skyscrapers. Sad
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Thu Oct 30, 2008 10:37 pm    Post subject: Reply with quote

ravel,

I believe your r8c3<>2 elimination is just another way of seeing the Medusa Wrap.

I, too, saw the UR based r9c2 elimination, but didn't include it because didn't help much. I found it based on the UR-induced strong link, however, which is just an alternate way to see the same thing:
(2=3)r8c3 - UR[(3)r9c2=(5)r79c8] - (5=2)r9c9


Craig,

While you used the ER in b9 as an ER (a grouped strong link between a box-row segment and a box-column segment), you are using the <2>s in b2 as a grouped strong link between two box-column segments, not as an ER. Works the same way, but isn't the same thing.
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