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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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 Posted: Wed Aug 27, 2008 10:28 pm Post subject: Low Rated Menneske |
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I'm back!
(Africa was wonderful! Three weeks without the internet, radio, TV, or newspapers. Mostly by choice.)
I tried to solve this one on the plane flight home.
| Code: | Puzzle: M1748418vh
+-------+-------+-------+
| 7 2 . | . . 6 | . . . |
| . . . | 4 . . | 8 . . |
| . . 3 | . . . | . . . |
+-------+-------+-------+
| . . 7 | . . . | . . 6 |
| . . 9 | . 2 . | . . 5 |
| 6 . . | . 5 4 | . . . |
+-------+-------+-------+
| 9 . 6 | . . 1 | . 3 . |
| 1 7 . | . 9 . | 2 . . |
| . . . | 7 . . | 1 . . |
+-------+-------+-------+ |
After much more than basics, I am up to here:
| Quote: | +----------------+----------------+----------------+
| 7 2 48 | 1358 138 6 | 49 459 349 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
+----------------+----------------+----------------+
| 23 5 7 | 1389 138 38 | 49 1249 6 |
| 48 14 9 | 6 2 7 | 3 18 5 |
| 6 13 28 | 139 5 4 | 7 1289 289 |
+----------------+----------------+----------------+
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 | 38 9 358 | 2 6 48 |
| 23 34 245 | 7 6 58 | 1 489 489 |
+----------------+----------------+----------------+ |
Keith |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Thu Aug 28, 2008 1:47 am Post subject: |
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not looking at the white area... these are my first few steps. these steps do not complete it. 
| Code: | .---------------------.---------------------.---------------------.
| 7 2 48 | 13589 138 6 | 349 1459 1349 |
| 5 6 1 | 4 37 239 | 8 279 239 |
| 48 9 3 | 158 178 258 | 6 12457 124 |
:---------------------+---------------------+---------------------:
| 2348 5 7 | 1389 138 389 | 349 12489 6 |
| 348 134 9 | 6 2 7 | 34 148 5 |
| 6 13 28 | 1389 5 4 | 7 1289 12389 |
:---------------------+---------------------+---------------------:
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 | 358 9 358 | 2 6 48 |
| 234 34 245 | 7 6 58 | 1 489 489 |
'---------------------'---------------------'---------------------' |
I think most would find the xyz-wing
coloring on 4
edit:
I made a blunder here. sorry about that.
Last edited by storm_norm on Thu Aug 28, 2008 8:31 pm; edited 1 time in total |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Thu Aug 28, 2008 1:49 am Post subject: |
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Hi Keith, welcome back. Glad you enjoyed your technology-free vacation.
This was an interesting puzzle, just as challenging as many of the Super Hards. For me, it took three ERs, a Finned X-Wing and breaking up a DP on an almost Type 6. |
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wapati
Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
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| Posted: Thu Aug 28, 2008 2:52 am Post subject: Re: Low Rated Menneske |
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| keith wrote: | I'm back!
(Africa was wonderful! Three weeks without the internet, radio, TV, or newspapers. Mostly by choice.)
Keith |
There is no chance I would accept that, happy for you that you can! |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Thu Aug 28, 2008 2:16 pm Post subject: |
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| storm_norm wrote: | ... the extended w-wing marked below ...
removes the 8 in r6c9 |
I cant see that. The pairs 48 in r1c3 and r8c9 are only a "half m-wing" with the strong link for 4 in row 8. I.e. from r8c9=8 follows r1c3=8, but not r8c9=4 => r1c3=4.
This is a cumbersome puzzle.
skyscraper 9, kite 4, xyz-wing 134, xy-wing 238 brought me here:
| Code: | *-------------------------------------------------*
| 7 2 48 | 1358 138 6 |#49 #459 349 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------+-----------------+----------------|
| 23 5 7 | 189 138 38 |#49 #1249 6 |
| 48 14 9 | 6 2 7 | 3 18 5 |
| 6 13 28 | 139 5 4 | 7 1289 289 |
|--------------+-----------------+----------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 @45 | 38 9 @358 | 2 6 @48 |
| 23 34 @245 | 7 6 @58 | 1 489 @489 |
*-------------------------------------------------* |
Then two uniqueness eliminations, which did not help much:
UR 49 in r14c78, strong link 4 in r4, r1c8<>9
DP 45-58-48 in r89c369, x-wing 5, strong link 4 in r8, r9c9<>4
[Edit:]Corrected the typo.
| Code: | *-------------------------------------------------*
| 7 2 48 | 1358 138 6 | 49 45 349 |
| 5 6 1 | 4 #37 9 | 8 27 *23 |
|*48 9 3 | 58 #78 2 | 6 457 1 |
|--------------+-----------------+----------------|
| 23 5 7 | 189 138 38 | 49 1249 6 |
|*48 14 9 | 6 2 7 | 3 18 5 |
| 6 13 *28 | 139 5 4 | 7 1289 -289 |
|--------------+-----------------+----------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 | 38 9 358 | 2 6 48 |
| 23 34 245 | 7 6 58 | 1 489 89 |
*-------------------------------------------------* |
When searching for generalized xy-wings i finally found this 6-cell xy-chain:
One of r2c5=3 and r3c5=8 must be true:
r2c5=3 => r2c9=2
r3c5=8 => r3c1=4 => r5c1=8 => r6c3=2
r6c9<>2
After that still a UR and xy-wing was needed.
Last edited by ravel on Fri Aug 29, 2008 8:45 am; edited 1 time in total |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Aug 28, 2008 4:53 pm Post subject: |
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The best I can find involves an XY-Chain and a UR.
| Code: | Where Keith's (valiant) initial effort stops
+--------------------------------------------------------------+
| 7 2 48 | 1358 138 6 | 49 459 349 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------------+--------------------+--------------------|
| 23 5 7 | 1389 138 38 | 49 1249 6 |
| 48 14 9 | 6 2 7 | 3 18 5 |
| 6 13 28 | 139 5 4 | 7 1289 289 |
|--------------------+--------------------+--------------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 | 38 9 358 | 2 6 48 |
| 23 34 245 | 7 6 58 | 1 489 489 |
+--------------------------------------------------------------+
# 56 eliminations remain
-5r8c3 4r8c3 3r9c2 2r9c1 3r4c1 8r4c6 5r9c6 [XY-Chain] <> 5 [r8c6],[r9c3]
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| Code: | +--------------------------------------------------------------+
| 7 2 48 | 1358 138 6 | 49 459 39 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------------+--------------------+--------------------|
| 23 5 7 | 1389 138 38 | 49 1249 6 |
| 48 14 9 | 6 2 7 | 3 *18 5 |
| 6 13 *28 | 139 5 4 | 7 89+12 89+2 |
|--------------------+--------------------+--------------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 5 | 38 9 38 | 2 6 4 |
| 23 34 24 | 7 6 5 | 1 89 89 |
+--------------------------------------------------------------+
# 48 eliminations remain
(38) UR Type 1 [r48c46] <> 38 [r4c4] IGNORE!
(89) UR Type ? [r69c89] <> 8 [r6c89]
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Note to Keith: Remember all of the trouble I had (in the Players' Forums) learning the DP pattern in a basic UR? I bet you thought that I'd never learn to spot any kind of UR. Well, you'd still be mostly right.  |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Thu Aug 28, 2008 8:30 pm Post subject: |
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| Quote: | | I cant see that. The pairs 48 in r1c3 and r8c9 are only a "half m-wing" with the strong link for 4 in row 8. I.e. from r8c9=8 follows r1c3=8, but not r8c9=4 => r1c3=4. |
wow, you are right, total blunders on my part. |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Thu Aug 28, 2008 8:31 pm Post subject: |
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| daj95376 wrote: | | (89) UR Type ? [r69c89] <> 8 [r6c89] |
Nice catch aagain. Dont know a type either. Maybe aligned pair UR ? |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Thu Aug 28, 2008 9:05 pm Post subject: |
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| ravel wrote: |
This is a cumbersome puzzle.
skyscraper 9, kite 4, xyz-wing 134, xy-wing 238 brought me here:
| Code: | *-------------------------------------------------*
| 7 2 48 | 1358 138 6 |#49 #459 349 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------+-----------------+----------------|
| 23 5 7 | 189 138 38 |#49 #1249 6 |
| 48 14 9 | 6 2 7 | 3 18 5 |
| 6 13 28 | 139 5 4 | 7 1289 289 |
|--------------+-----------------+----------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 @45 | 38 9 @358 | 2 6 @48 |
| 23 34 @245 | 7 6 @58 | 1 489 @489 |
*-------------------------------------------------* |
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I had a very similar sequence of eliminations. I noticed a finned x-wing destructively interacting with the skyscraper on <9> and took the eliminations from both, followed by a finned x-wing on <4> instead of the kite, then the xyz-wing <134> and the xy-wing <238>. At that point, my grid was identical to the posted grid except I had an additional <3> digit in r4c4. This condition in fact then offered a diagonal UR on <38> like a Type 3 with a strong link on <3> in col6 & row8 that deleted the <3> from r4c4 thereby matching the posted grid. I saw the UR on <49>, but missed the DP 45-58-48 in r89c369.
As I have previously commented, I am having a mental block with these MUG/DP conditions and in this case I am not able to follow the logic that removes <9> from r9c9.
Could someone please provide some details.
Thanks in advance .......
Ravel, I really admired the xy-chain to essentially finish off this puzzle.
Ted  |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Thu Aug 28, 2008 9:25 pm Post subject: |
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| daj95376 wrote: | The best I can find involves an XY-Chain and a UR.
| Code: | +--------------------------------------------------------------+
| 7 2 48 | 1358 138 6 | 49 459 39 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------------+--------------------+--------------------|
| 23 5 7 | 1389 138 38 | 49 1249 6 |
| 48 14 9 | 6 2 7 | 3 *18 5 |
| 6 13 *28 | 139 5 4 | 7 89+12 89+2 |
|--------------------+--------------------+--------------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 5 | 38 9 38 | 2 6 4 |
| 23 34 24 | 7 6 5 | 1 89 89 |
+--------------------------------------------------------------+
# 48 eliminations remain
(38) UR Type 1 [r48c46] <> 38 [r4c4] IGNORE!
(89) UR Type ? [r69c89] <> 8 [r6c89]
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If the <89> UR is treated as a normal Type 3 (by forgetting about the strong links), then the pseudo-cell <12> in box6 acts as the pivot for a xy-wing <128> that deletes <8> from r5c1 thereby finishing off the puzzle. The Type issue is then NOT an issue.
Ted |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Thu Aug 28, 2008 9:36 pm Post subject: |
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Ted,
Ravel mis-typed. It should be: r9c9<>4. r8c9 is either 4 or 8. If 8, then the 5 X-Wing collapses removing the 2 and 3 "extra" digits and leaving the 9 in r9c9 as the only way to avoid the DP. So either way, r9c9 is not 4.
I agree that the 89 UR is an XY-Wing equivalent, which is interesting. |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Thu Aug 28, 2008 9:39 pm Post subject: |
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From the same place as daj95376, I went right to Medusa:
| Code: |
+----------------+-----------------+----------------+
| 7 2 4a8A | 1358 138 6 | 49 459 349 |
| 5 6 1 | 4 37 9 | 8 27 23 |
|@4a8A 9 3 |#5-8 78 2 | 6 4A57 1 |
+----------------+-----------------+----------------+
| 23 5 7 | 1389 138 38 | 49 12a49 6 |
| 4A8a 1A4a 9 | 6 2 7 | 3 1a8A 5 |
| 6 1a3A 2a8A |@13a9 5 4 | 7 1289 289 |
+----------------+-----------------+----------------+
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 |@38(a) 9 358 | 2 6 48 |
| 2a3A 3a4A 2A45 | 7 6 58 | 1 489 489 |
+----------------+-----------------+----------------+
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The 3a at r6c4 is easily "transported" (or simply multi-colored) to 8a at r8c4, trapping <8> at r3c4.
This leads immediately to a "wrap":
| Code: |
+----------------+-----------------+----------------+
| 7 2 4a8A | 1358 138 6 | 49 459 349 |
| 5 6 1 | 4 3A7a 9 | 8 #2a7A 23 |
| 4a8A 9 3 | 5 7A8a 2 | 6 4A7a 1 |
+----------------+-----------------+----------------+
| 23 5 7 | 1389 138 38 | 49 #12a49 6 |
| 4A8a 1A4a 9 | 6 2 7 | 3 1a8A 5 |
| 6 1a3A 2a8A | 13a9 5 4 | 7 1289 289 |
+----------------+-----------------+----------------+
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 45 | 38 9 358 | 2 6 48 |
| 2a3A 3a4A 2A45 | 7 6 58 | 1 489 489 |
+----------------+-----------------+----------------+
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There are two 2a's in c8, so all the "a" values are false, solving the puzzle quite easily. |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Thu Aug 28, 2008 10:08 pm Post subject: |
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Thanks Asellus. I went back and reviewed Ravel's original input, and it is now obvious by looking at the resultant code that a typo occurred; I should have noticed that originally.
Ted |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu Aug 28, 2008 10:23 pm Post subject: |
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| tlanglet wrote: | | ... the pseudo-cell <12> in box6 acts as the pivot for a xy-wing <128> that deletes <8> from r5c1 ... |
I like it  _____ I keep forgetting that a pair of UR cells can often be treated as a pseudo-cell. |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Thu Aug 28, 2008 10:41 pm Post subject: |
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| tlanglet wrote: | | daj95376 wrote: | The best I can find involves an XY-Chain and a UR.
| Code: | +--------------------------------------------------------------+
| 7 2 48 | 1358 138 6 | 49 459 39 |
| 5 6 1 | 4 37 9 | 8 27 23 |
| 48 9 3 | 58 78 2 | 6 457 1 |
|--------------------+--------------------+--------------------|
| 23 5 7 | 1389 138 38 | 49 1249 6 |
| 48 14 9 | 6 2 7 | 3 *18 5 |
| 6 13 *28 | 139 5 4 | 7 89+12 89+2 |
|--------------------+--------------------+--------------------|
| 9 8 6 | 2 4 1 | 5 3 7 |
| 1 7 5 | 38 9 38 | 2 6 4 |
| 23 34 24 | 7 6 5 | 1 89 89 |
+--------------------------------------------------------------+
# 48 eliminations remain
(38) UR Type 1 [r48c46] <> 38 [r4c4] IGNORE!
(89) UR Type ? [r69c89] <> 8 [r6c89]
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If the <89> UR is treated as a normal Type 3 (by forgetting about the strong links), then the pseudo-cell <12> in box6 acts as the pivot for a xy-wing <128> that deletes <8> from r5c1 thereby finishing off the puzzle. The Type issue is then NOT an issue.
Ted |
Wow! I am impressed!
Is it correct to say that it also eliminates <8> in R6C89, the UR cells in R6?
Keith |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Thu Aug 28, 2008 10:48 pm Post subject: |
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| daj95376 wrote: | | Note to Keith: Remember all of the trouble I had (in the Players' Forums) learning the DP pattern in a basic UR? I bet you thought that I'd never learn to spot any kind of UR. Well, you'd still be mostly right. |
Danny,
That is not my recollection. I do remember you asking some challenging questions that forced me to reconsider and revise my explanations ...
Keith |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Thu Aug 28, 2008 11:55 pm Post subject: |
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| keith wrote: |
Is it correct to say that it also eliminates <8> in R6C89, the UR cells in R6?
Keith |
I saw the deletions of <8> in box6 but did not mention them since I am not sure if they are valid. I assume they are based on a comment by a person named "Keith" who once noted that interactions of solutions do not invalidate the separate solutions.
Ted |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Fri Aug 29, 2008 2:44 am Post subject: |
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| Quote: | | If the <89> UR is treated as a normal Type 3 (by forgetting about the strong links), then the pseudo-cell <12> in box6 acts as the pivot for a xy-wing <128> that deletes <8> from r5c1 thereby finishing off the puzzle. The Type issue is then NOT an issue. |
that's impressive enough to use on a geeky date |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Fri Aug 29, 2008 8:43 am Post subject: |
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| tlanglet wrote: | | I am not able to follow the logic that removes <9> from r9c9. |
I am very sorry about this typo (thanks to Asellus to clarify that). I do know the troubles you can have, if you believe a typo.
Concerning Danny's xy UR: A simple way to understand it was often used in this forum. Since one of the extra candidates must be true, look, what it implies, i.e. (in sudoku terms) try a (multiple) forcing chain. In this case one of
r6c8=1 => r5c8=8
r6c89=2 => r6c3=8
must be true.
We have seen many of similar, often more complex deductions here, especially by Johan.
Anyway this special pattern has its own charm. |
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cgordon
Joined: 04 May 2007
Posts: 769
Location: ontario, canada
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| Posted: Fri Aug 29, 2008 5:45 pm Post subject: |
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| I used two ER’s, a skyscraper, an xyz-wing , an xy-wing, colouring on <4>, a diagonal variant of a Type 4 UR (Type 6??), and one of them funny UR’s on <38> that Nataraj recently referred to as weasels. But still can’t solve it . I guess it needs xy-chains and stuff that ain't in my arsenal. |
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