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ravel
Joined: 21 Apr 2006
Posts: 536
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 Posted: Tue Feb 26, 2008 9:34 am Post subject: Another nice pattern |
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| Code: | 1 . . 4 3 . . 9 .
. . . 9 5 . . . .
. 6 . . . . 2 . .
. . . . . . . . .
8 . . . . . . 4 .
2 3 . . . . 7 1 .
. 1 . 7 9 . 6 . .
4 . . 3 8 . . 5 .
. . . . . . . . . m_b_metcalf
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>>> play online
Dont hurry with the uniqueness eliminations. |
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Victor
Joined: 29 Sep 2005
Posts: 207
Location: NI
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| Posted: Tue Feb 26, 2008 11:52 am Post subject: |
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Just printed it out.
| Quote: | | Dont hurry with the uniqueness eliminations. |
Hard to resist! - but I'll try. |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Tue Feb 26, 2008 1:09 pm Post subject: |
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I did not mean that you shouldn't solve the puzzle with them  |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Tue Feb 26, 2008 6:58 pm Post subject: |
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| I used a W-Wing, XY-Wing, two Type 4 URs (don't know if I "hurried" into them), then finished it off with Medusa (reluctantly, but I didn't see anything else). |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Tue Feb 26, 2008 6:59 pm Post subject: |
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Ravel,
are you done with this forum after 999 posts as you stated you are in the players forum? |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Tue Feb 26, 2008 7:22 pm Post subject: |
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| Code: | |---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9--
-----------------------------------------------------------------------------
r1 | 1 | 2 | 58 || 4 | 3 | 6 || 58 | 9 | 7
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r2 | 7 | 48 | 3 || 9 | 5 | 2 || 14 | 6 | 148
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r3 | 59 | 6 | 459 || 18 | 17 | 78 || 2 | 3 | 45
===========================||=======================||=======================
r4 | 6 | 459 | 17 || 158 | 147 | 3789 || 358 | 2 | 589
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r5 | 8 | 59 | 17 || 1256 | 1267 | 379 || 35 | 4 | 569
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r6 | 2 | 3 | 459 || 568 | 46 | 89 || 7 | 1 | 5689
===========================||=======================||=======================
r7 | 35 | 1 | 2 || 7 | 9 | 45 || 6 | 8 | 34
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r8 | 4 | 7 | 6 || 3 | 8 | 1 || 9 | 5 | 2
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r9 | 359 | 589 | 589 || 26 | 26 | 45 || 14 | 7 | 134
............................................................................. |
this was no picnic up to this point.
so this is one of those 8X8 whatever they are called. |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Tue Feb 26, 2008 8:13 pm Post subject: |
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I believe these URs are both type 4.
UR {1,4} removes 4 from r2c9 and r9c9
UR {2,6} removes 6 from r5c4 and r5c5
xy-wing {3,4,5} removes 5 from r3c1
xy-chain starting with r5c2 59-49-45-58-58 removes 5 in r5c7
xy-chain starting with r5c3 17-79-89-78-17 removes 1 from r5c5
xy-chain starting in r6c3 49-46-26-27-79 sees nines in r6c6 and r5c2
xy-wing{4,5,9} removes 5 from r3c9 |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Tue Feb 26, 2008 9:27 pm Post subject: |
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After the xy-wing (pivot r7c9) and resulting cleanup, this is where I used 2 URs:
| Code: |
+--------------------------+--------------------------+--------------------------+
| 1 2 58 | 4 3 6 | 58 9 7 |
| 7 48 3 | 9 5 2 | 14 6 148 |
| 9 6 45 | 18 17 78 | 2 3 45 |
+--------------------------+--------------------------+--------------------------+
| 6 459 17 | 158 147 3789 | 358 2 589 |
| 8 59 17 | 1256 1267 379 | 35 4 569 |
| 2 3 49 | 568 46 89 | 7 1 5689 |
+--------------------------+--------------------------+--------------------------+
| 35 1 2 | 7 9 45 | 6 8 34 |
| 4 7 6 | 3 8 1 | 9 5 2 |
| 35 89 89 | 26 26 45 | 14 7 134 |
+--------------------------+--------------------------+--------------------------+
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a) possible DP 35 45 34 in boxes 7,8,9 gives r9c9=1
b) UR 26 combined with x-wing 2 gives r5c9=6
But then ... needed an xy-chain, which removed 5 from r5c7:
'58'(r1c7)...r1c3,r3c3,r6c3...'59'(r5c2)
AND another one which removed 8 from r6c9
'84'(29)...r3c9,r3c3,r6c3...'89'(r6c6)
An xy-wing 49-59-45 finally finishd it off
---
BTW, I just realized I have Ravel playing on the CD - concert pour la main gauche. very nice |
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Steve R
Joined: 24 Oct 2005
Posts: 289
Location: Birmingham, England
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| Posted: Wed Feb 27, 2008 12:27 am Post subject: |
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I seem to think of nothing but uniqueness at the moment.
These are the entries to Norman’s grid. The cells containing 2 and 6 are marked with an asterisk
| Code: | +-----------------------------+
| 1 2* . | 4 3 6* | . 9 7 |
| 7 . 3 | 9 5 2* | . 6* . |
| . 6* . | . . . | 2* 3 . |
-------------------------------
| 6* . . | . . . | . 2* . |
| 8 . . | . . . | . 4 . |
| 2* 3 . | . . . | 7 1 . |
-------------------------------
| . 1 2* | 7 9 . | 6* 8 . |
| 4 7 6* | 3 8 1 | 9 5 2* |
| . . . | . . . | . 7 . |
+-----------------------------+ |
If r6c9 were to contain a 6, the asterisked cells would form a (26) unavoidable set. In other words the reverse BUG Light eliminates 6 from r6c9 and so places 6 in r5c9.
This is a useful step forward although it does not itself solve the puzzle.
Steve |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Wed Feb 27, 2008 4:49 am Post subject: |
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| Quote: | | This is a useful step forward although it does not itself solve the puzzle |
of course when you say "useful" that is an understatement, correct?? |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Wed Feb 27, 2008 6:15 am Post subject: |
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I did this puzzle earlier then was surprised to come back and read about XY Chains and Medusa.
(1) Type 4 {25} UR r59c45 removes <6> from r5c45
(2) XY Wing pivot r7c9 removes <5> from r3c1
(3) Two mutually destructive DPs considered together (perhaps this is what Ravel meant by not hurrying?):
- The {53}{45}{34} in r79c169 mentioned by nataraj that makes r9c9=1
- Type 4 {14} UR r29c79 removes <4> from r29c9
(Either of these last two DP determinations are still valid after applying the other, though that makes them more difficult to see.) |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Wed Feb 27, 2008 10:22 am Post subject: |
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Thats exactly, what i meant. I did the type 4 UR's first and then found the 6 cell DP, but a 4 was missing in the pattern. Probably harder to spot is the UR 14 elimination, when you first set r9c9 to 1, as nataraj had done.
Nice catch, Steve R, those reverse BUG's are rare things and i never look for them. The (remaining) UR 26 here leads to the same placement.
| storm_norm wrote: | | are you done with this forum after 999 posts as you stated you are in the players forum? |
Lets see first, if i live that long |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Wed Feb 27, 2008 4:53 pm Post subject: |
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| Quote: | storm_norm wrote:
are you done with this forum after 999 posts as you stated you are in the players forum?
Lets see first, if i live that long |
Ravel,
Since you joined you've averaged about 13.5 posts per month. If you maintain that rate, you'll hit 999 in about June 2012, so I won't worry about losing you just yet.  |
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