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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Fri Jun 27, 2008 9:57 pm Post subject: LA Times / Freep - June 27, 2008 |
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Not yet solved: Code: | Puzzle: FP062708
+-------+-------+-------+
| . . . | . 4 2 | 7 . . |
| . 2 . | . 1 . | . 6 4 |
| . 1 . | . . . | 5 . . |
+-------+-------+-------+
| 1 . . | 7 . . | 6 . . |
| 6 7 . | . . . | . 2 5 |
| . . 2 | . . 8 | . . 1 |
+-------+-------+-------+
| . . 4 | . . . | . 5 . |
| 2 9 . | . 6 . | . 3 . |
| . . 7 | 2 8 . | . . . |
+-------+-------+-------+
| Keith |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Fri Jun 27, 2008 10:15 pm Post subject: |
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This one is surprisingly tough, unless I'm missing something. It took me 5 steps: XY-Wing; Sashimi Swordfish; Turbot Fish (or ER); XY-Wing; W-Wing. |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Fri Jun 27, 2008 10:47 pm Post subject: |
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Asellus wrote: | This one is surprisingly tough, unless I'm missing something. It took me 5 steps: XY-Wing; Sashimi Swordfish; Turbot Fish (or ER); XY-Wing; W-Wing. |
You solved it? Basics get me to here: Code: | +----------------+----------------+----------------+
| 3589 358 6 | 3589 4 2 | 7 1 389 |
| 7 2 3589 | 3589 1 359 | 389 6 4 |
| 4 1 389 | 389 7 6 | 5 89 2 |
+----------------+----------------+----------------+
| 1 3458 3589 | 7 2 349 | 6 489 389 |
| 6 7 389 | 1349 39 1349 | 3489 2 5 |
| 39 34 2 | 6 5 8 | 349 7 1 |
+----------------+----------------+----------------+
| 38 368 4 | 139 39 1379 | 2 5 679 |
| 2 9 1 | 45 6 457 | 48 3 78 |
| 35 356 7 | 2 8 349 | 1 49 69 |
+----------------+----------------+----------------+ | There is an XY-wing 48-49-89 that takes out <8> in R2C7. With coloring on that same wing, you can take out <8> in R3C3. Leaving me here: Code: | +----------------+----------------+----------------+
| 3589 358 6 | 3589 4 2 | 7 1 389 |
| 7 2 3589 | 3589 1 359 | 39 6 4 |
| 4 1 39 | 389 7 6 | 5 89 2 |
+----------------+----------------+----------------+
| 1 3458 3589 | 7 2 349 | 6 489 389 |
| 6 7 389 | 1349 39 1349 | 3489 2 5 |
| 39 34 2 | 6 5 8 | 349 7 1 |
+----------------+----------------+----------------+
| 38 368 4 | 139 39 1379 | 2 5 679 |
| 2 9 1 | 45 6 457 | 48 3 78 |
| 35 356 7 | 2 8 349 | 1 49 69 |
+----------------+----------------+----------------+ | And, I am stuck.
Keith |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Sat Jun 28, 2008 12:48 am Post subject: |
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Keith,
That r3c3 elimination can also be seen as a Kite. You need the Sashimi Swordfish. It's in r235. See if you can spot it. |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Sat Jun 28, 2008 1:20 am Post subject: |
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after basics
Code: | .------------------.------------------.------------------.
| 3589 358 6 | 3589 4 2 | 7 1 389 |
| 7 2 3589 | 3589 1 359 | 389 6 4 |
| 4 1 389 | 389 7 6 | 5 89 2 |
:------------------+------------------+------------------:
| 1 3458 3589 | 7 2 349 | 6 489 389 |
| 6 7 389 | 1349 39 1349 | 3489 2 5 |
| 39 34 2 | 6 5 8 | 349 7 1 |
:------------------+------------------+------------------:
| 38 368 4 | 139 39 1379 | 2 5 679 |
| 2 9 1 | 45 6 457 | 48 3 78 |
| 35 356 7 | 2 8 349 | 1 49 69 |
'------------------'------------------'------------------' |
I will go along with the xy-wing to remove 8 from r2c7
coloring 8...
ER {3}
which leads to this...
Code: | .------------------.------------------.------------------.
| 3589 358 6 | 3589 4 2 | 7 1 #389 |
| 7 2 #3589 |#3589 1 359 | 39 6 4 |
| 4 1 39 |3-89 7 6 | 5 #89 2 |
:------------------+------------------+------------------:
| 1 3458 589 | 7 2 349 | 6 489 389 |
| 6 7 #389 | 1349 39 1349 |#3489 2 5 |
| 39 34 2 | 6 5 8 | 349 7 1 |
:------------------+------------------+------------------:
| 38 368 4 | 139 39 1379 | 2 5 679 |
| 2 9 1 | 45 6 457 |#48 3 #78 |
| 35 356 7 | 2 8 349 | 1 49 69 |
'------------------'------------------'------------------' |
there is a cycle on 8 marked
(8)r2c4=(8)r2c3-(8)r5c3=(8)r5c7-(8)r8c7=(8)r8c9-(8)r1c9=(8)r3c8; r3c4<>8
one coloring move removes 9 from r1c1.
xy-wing {3,4,9} removes the 9 in r5c7 |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Sat Jun 28, 2008 4:05 am Post subject: |
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The Sashimi Swordfish can also be viewed like Norm's 8-cycle of weakly connected conjugate (strong) links, though it is shorter:
(8)r3c8=(8)r3c4 - (8)r2c4=(8)r2c3 - (8)r5c3=(8)r5c7; r4c8<>8
The missing Swordfish bit is r5c8. The result is the same as Norm's cycle.
The full details of my solution path, after the XY-Wing and Sashimi Swordfish, are:
[3] Turbot Fish (or Color Wing or ER) in c1-r1-b3 removes <9> from r6c7
[4] XY-Wing, pivot r6c7, removes <9> from r5c7 (Same as Norm's)
[5] 34 WWing in r46, <4> strong link in c2, removes 3 from r4c9 |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Sat Jun 28, 2008 7:53 am Post subject: |
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I have to credit Ravel for his views on catching useless kites as in the cycle example, which combines a useless kite on 8 with two shorter conjugate strings. |
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