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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Wed Feb 23, 2011 1:24 pm Post subject: Another interesting one |
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Another interesting one.
Code: | Puzzle: M3799253sh(16)
+-------+-------+-------+
| . 7 3 | . . 4 | . . 1 |
| . . 9 | . . 6 | . 4 . |
| . 5 . | . 2 . | . 6 . |
+-------+-------+-------+
| . . . | . . . | 5 3 6 |
| . . . | . . . | . . . |
| 4 8 7 | . . . | . . . |
+-------+-------+-------+
| . 9 . | . 7 . | . 5 . |
| . 4 . | 5 . . | 6 . . |
| 3 . . | 4 . . | 9 8 . |
+-------+-------+-------+ | Keith |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Wed Feb 23, 2011 7:52 pm Post subject: |
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Whatever solution was there escaped me. I played an ER, M-Wing and W-Wing to no avail. A Medusa trap exposed a flightless XY-Wing with a couple of transports followed by a Medusa placement which finished things off. |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Wed Feb 23, 2011 8:07 pm Post subject: |
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[1] 6-cell 12DP B147[(8)r2c1=(8)r7c3] - (8)r7c6=(8)r8c5; r2c5<>8
(i.e. a simple transport of one of the <8>s in the DP)
[2] 289XYW; r6c7<>2 |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Wed Feb 23, 2011 9:18 pm Post subject: |
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After basics: Code: | +----------------+----------------+----------------+
| 6 7 3 | 89 5 4 | 28@ 29@ 1 |
| 128% 12 9 | 178 38$ 6 | 378 4 5 |
| 18 5 4 | 1789 2 378 | 378 6 389 |
+----------------+----------------+----------------+
| 9 12 12 | 78 4 78 | 5 3 6 |
| 5 3 6 | 2 9 1 | 48 7 48 |
| 4 8 7 | 3 6 5 | 12# -129 29 |
+----------------+----------------+----------------+
| 12 9 128% | 6 7 38 |-1234 5 234 |
| 7 4 12-8 | 5 38$ 9 | 6 12# 23 |
| 3 6 5 | 4 1 2 | 9 8 7 |
+----------------+----------------+----------------+ |
DP noted by Asellus, I think. Either % R2C1 is 8 and/or R7C3 is 8. Note the strong link $8 in C5. Either way, R8C3 <>8. (Transport R2C1.)
Then a W-wing @# (noted by Marty?) in B369.
How sweet it is.
Keith |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Wed Feb 23, 2011 9:32 pm Post subject: |
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Asellus' <12> DP can be combined with coloring to perform two extra eliminations.
Code: | Blue Green Blue Green Blue
(8)r2c5 - r8c5 = r8c3 - <12> DP [(8)r7c3 = (8)r2c1]
+--------------------------------------------------------------+
| 6 7 3 | 89 5 4 | 28 29 1 |
| B128 12 9 | 178 B38 6 | 378 4 5 |
| 18 5 4 | 1789 2 378 | 378 6 389 |
|--------------------+--------------------+--------------------|
| 9 12 12 | 78 4 78 | 5 3 6 |
| 5 3 6 | 2 9 1 | 48 7 48 |
| 4 8 7 | 3 6 5 | 12 129 29 |
|--------------------+--------------------+--------------------|
| 12 9 G128 | 6 7 38 | 1234 5 234 |
| 7 4 B128 | 5 G38 9 | 6 12 23 |
| 3 6 5 | 4 1 2 | 9 8 7 |
+--------------------------------------------------------------+
# 45 eliminations remain
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The Blue cells -- r2c1, r2c5, and r8c3 -- must be false. Singles complete the puzzle.
The five cell pattern connected by 4x strong links reminds me of a Broken Wing pattern where r2c4 and r2c7 act as guardian cells. |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Thu Feb 24, 2011 5:53 am Post subject: |
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A different route: From the "after basics" grid above:
A grouped skyscraper in C67 takes out 3 in C39.
After an XY-wing -289 in C79 we are here:
Code: | +----------------+----------------+----------------+
| 6 7 3 | 89 5 4 | 28 29 1 |
| 128 12 9 | 178 38 6 | 37 4 5 |
| 18 5 4 | 1789 2 378 | 37 6 89 |
+----------------+----------------+----------------+
| 9 12 12 | 78 4 78 | 5 3 6 |
| 5 3 6 | 2 9 1 | 48 7 48 |
| 4 8 7 | 3 6 5 | 1 29 29 |
+----------------+----------------+----------------+
| 12 9 128 | 6 7 38 | 24 5 234 |
| 7 4 28 | 5 38 9 | 6 1 23 |
| 3 6 5 | 4 1 2 | 9 8 7 |
+----------------+----------------+----------------+ |
M-wing: 8 In R8C3 forces 8 in R1C7. R8C3 and R7C7 are pincers on 2, puzzle is solved.
Keith |
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Asellus
Joined: 05 Jun 2007 Posts: 865 Location: Sonoma County, CA, USA
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Posted: Thu Feb 24, 2011 9:29 am Post subject: |
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daj95376 wrote: | Asellus' <12> DP can be combined with coloring to perform two extra eliminations.
Code: | Blue Green Blue Green Blue
(8)r2c5 - r8c5 = r8c3 - <12> DP [(8)r7c3 = (8)r2c1]
+--------------------------------------------------------------+
| 6 7 3 | 89 5 4 | 28 29 1 |
| B128 12 9 | 178 B38 6 | 378 4 5 |
| 18 5 4 | 1789 2 378 | 378 6 389 |
|--------------------+--------------------+--------------------|
| 9 12 12 | 78 4 78 | 5 3 6 |
| 5 3 6 | 2 9 1 | 48 7 48 |
| 4 8 7 | 3 6 5 | 12 129 29 |
|--------------------+--------------------+--------------------|
| 12 9 G128 | 6 7 38 | 1234 5 234 |
| 7 4 B128 | 5 G38 9 | 6 12 23 |
| 3 6 5 | 4 1 2 | 9 8 7 |
+--------------------------------------------------------------+
# 45 eliminations remain
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The Blue cells -- r2c1, r2c5, and r8c3 -- must be false. |
Danny,
I believe you were lucky in this case. Care must be taken when coloring from a DP-induced strong inference. This is actually multi-coloring:
Code: | +--------------------------------------------------------------+
| 6 7 3 | 89 5 4 | 28 29 1 |
| 128B 12 9 | 178 38g 6 | 378 4 5 |
| 18 5 4 | 1789 2 378 | 378 6 389 |
|--------------------+--------------------+--------------------|
| 9 12 12 | 78 4 78 | 5 3 6 |
| 5 3 6 | 2 9 1 | 48 7 48 |
| 4 8 7 | 3 6 5 | 12 129 29 |
|--------------------+--------------------+--------------------|
| 12 9 128G | 6 7 38 | 1234 5 234 |
| 7 4 128g | 5 38G 9 | 6 12 23 |
| 3 6 5 | 4 1 2 | 9 8 7 |
+--------------------------------------------------------------+ |
I've revised your color markings. Two color groups, Bb and Gg, propagate from the DP strong inference. Only B and G can eliminate , or "trap," candidates (hence the elimination of <8> in r2c5). Note that bg is a weak inference pair and so cannot make eliminations. There is no "wrap" of two Bs in row 2 so we don't know the status of the <8> in r2c1 from this. (r8c3<>8 because the Gg group collapses from the elimination.)
Most multi-coloring exploits a weak inference "bridge" between two color groups. However a strong inference can also be used to bridge two groups, as was done here. In either case, one must be careful to distinguish the weak inference and strong inference color pairs and not to confuse the two separate color groups. |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Thu Feb 24, 2011 4:02 pm Post subject: |
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Asellus: Yes, upon review, I realize that I'd applied coloring based on one direction of my logic. If I'd started at r2c1 with the assumption that Blue was true, then I could not then assume that cell r7c3 is Green. (In fact, I'd previously determined that r7c3 was always true.)
The <12> DP has a strong inference but not a weak inference!!! This is probably rephrasing your reply.
Thanks for catching my oversight.
Regards, Danny |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Fri Feb 25, 2011 3:40 pm Post subject: |
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Three deadly pattern based steps.........
#1 6-cell ADP(12)r247[(8)r2c1=(8)r7c3-r7c6-(8)r8c5; r2c5<>8
#2. Type 1 UR(78)r34c69; r3c4<>78
#3: BUG+3: sis r2c1=1 or r6c8=2 or r7c7=2; r3c1<>1=8
Ted |
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