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ravel
Joined: 21 Apr 2006
Posts: 536
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 Posted: Mon Apr 28, 2008 10:27 am Post subject: VH's by Tarek |
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On the Player's forum Tarek published a list with many hundreds of fully symmetriacal puzzles with 20 givens. Many of them seem to be interesting to solve. Here are 3 VH's:
| Code: | +-------+-------+-------+
| . . . | . . . | . . . |
| . . 2 | . 4 . | 7 . . |
| . 8 . | 2 . 5 | . 9 . |
+-------+-------+-------+
| . . 4 | . . . | 3 . . |
| . 9 . | . . . | . 5 . |
| . . 6 | . . . | 4 . . |
+-------+-------+-------+
| . 5 . | 1 . 8 | . 6 . |
| . . 7 | . 6 . | 1 . . |
| . . . | . . . | . . . |
+-------+-------+-------+
|
>>> play online
| Code: | +-------+-------+-------+
| . . . | . 2 . | . . . |
| . . . | 4 3 6 | . . . |
| . . 5 | . . . | 8 . . |
+-------+-------+-------+
| . 2 . | . . . | . 4 . |
| 4 1 . | . . . | . 9 3 |
| . 3 . | . . . | . 5 . |
+-------+-------+-------+
| . . 7 | . . . | 6 . . |
| . . . | 9 4 5 | . . . |
| . . . | . 1 . | . . . |
+-------+-------+-------+
|
>>> play online
| Code: | +-------+-------+-------+
| . . 1 | . . . | 5 . . |
| . 5 . | . 9 . | . 2 . |
| 3 . . | . . . | . . 9 |
+-------+-------+-------+
| . . . | 1 . 5 | . . . |
| . 6 . | . . . | . 3 . |
| . . . | 7 . 8 | . . . |
+-------+-------+-------+
| 4 . . | . . . | . . 7 |
| . 9 . | . 2 . | . 6 . |
| . . 7 | . . . | 1 . . |
+-------+-------+-------+
|
>>> play online |
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sheryl
Joined: 24 Sep 2007
Posts: 64
Location: New York
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| Posted: Wed Apr 30, 2008 1:21 pm Post subject: |
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| thanks, these were fun. not necessarily easy, but, for me, doable! |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Thu May 01, 2008 12:05 am Post subject: |
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#1 after basics
| Code: | .---------------------.---------------------.---------------------.
| 3467 3467 5 | 367 9 1367 | 8 1234 1234 |
| 9 36 2 | 8 4 136 | 7 13 5 |
| 347 8 1 | 2 37 5 | 6 9 34 |
:---------------------+---------------------+---------------------:
| 1257 127 4 | 679 58 267 | 3 178 16789 |
| 37 9 8 | 3467 1 3467 | 2 5 67 |
| 12357 1237 6 | 379 58 237 | 4 178 1789 |
:---------------------+---------------------+---------------------:
| 24 5 3 | 1 27 8 | 9 6 247 |
| 8 24 7 | 5 6 9 | 1 234 234 |
| 16 16 9 | 347 237 347 | 5 278 278 |
'---------------------'---------------------'---------------------' |
each step through the advanced moves depends on the one before.
x-wing on 4 eliminates a 4 in r1c1
this in turn opens up the xyz-wing in box 1 {3,6,7} which eliminates the 3 in r3c1
this opens up the xy-wing {2,4,7} in r3c1, r7c1 and r7c5
eliminates the 7 in r3c5... done.
------------------
#2
| Code: | .---------------------.---------------------.---------------------.
| 136 79 34 | 5 2 8 | 49 36 1479 |
| 8 79 12 | 4 3 6 | 59 27 12579 |
| 236 46 5 | 7 9 1 | 8 36 24 |
:---------------------+---------------------+---------------------:
| 5 2 8 | 3 7 9 | 1 4 6 |
| 4 1 6 | 8 5 2 | 7 9 3 |
| 7 3 9 | 1 6 4 | 2 5 8 |
:---------------------+---------------------+---------------------:
| 9 45 7 | 2 8 3 | 6 1 45 |
| 126 68 12 | 9 4 5 | 3 278 27 |
| 23 458 34 | 6 1 7 | 459 28 459 |
'---------------------'---------------------'---------------------' |
two xy-wings, the first one {3,4,6} pivot in r1c3, eliminates 3's in r3c8 and r1c1
that opens up the {1,2,3} xy-wing pivot in r1c1 eliminates 2's in r8c3 and r3c1
---------------
#3
| Code: | .------------------.------------------.------------------.
| 9 48 1 | 236 7 236 | 5 48 36 |
| 6 5 48 | 34 9 1 | 7 2 348 |
| 3 7 2 | 8 5 46 | 46 1 9 |
:------------------+------------------+------------------:
| 8 34 349 | 1 36 5 | 2469 7 246 |
| 7 6 5 | 29 4 29 | 8 3 1 |
| 2 1 349 | 7 36 8 | 469 459 456 |
:------------------+------------------+------------------:
| 4 238 6 | 359 1 39 | 239 58 7 |
| 1 9 -38 | 345 2 7 |#34 6 58 |
| 5 #23 7 | 3469 8 3469 | 1 49 #24 |
'------------------'------------------'------------------' |
one xy-wing marked above, {2,3,4} pivot in r9c9 elimates the 3 in r8c3 |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Thu May 01, 2008 7:50 am Post subject: |
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Number one in one move:
extended xy-wing. Pincers 3,4 and 2,4 (marked #) r3c9, r7c1
Pivot (37-72 marked *) r3c5, r7c5
| Code: |
+--------------------------+--------------------------+--------------------------+
| 3467 3467 5 | 367 9 1367 | 8 1234 1234 |
| 9 36 2 | 8 4 136 | 7 13 5 |
| 3-47 8 1 | 2 37* 5 | 6 9 34# |
+--------------------------+--------------------------+--------------------------+
| 1257 127 4 | 679 58 267 | 3 178 16789 |
| 37 9 8 | 3467 1 3467 | 2 5 67 |
| 12357 1237 6 | 379 58 237 | 4 178 1789 |
+--------------------------+--------------------------+--------------------------+
| 24# 5 3 | 1 27* 8 | 9 6 2-47 |
| 8 24 7 | 5 6 9 | 1 234 234 |
| 16 16 9 | 347 237 347 | 5 278 278 |
+--------------------------+--------------------------+--------------------------+
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Thu May 01, 2008 3:39 pm Post subject: |
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| Quote: | extended xy-wing. Pincers 3,4 and 2,4 (marked #) r3c9, r7c1
Pivot (37-72 marked *) r3c5, r7c5 |
How does this differ from an XY-Chain? |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Thu May 01, 2008 4:08 pm Post subject: |
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| Marty R. wrote: | | Quote: | extended xy-wing. Pincers 3,4 and 2,4 (marked #) r3c9, r7c1
Pivot (37-72 marked *) r3c5, r7c5 |
How does this differ from an XY-Chain? |
It does not. It IS an xy-chain.
Strictly speaking, an xy-wing is also an xy-chain with 3 cells. W-wing is an xy-chain with 4 cells.
I called it an extended xy-wing because of the way I found it: first the two pincers (34 and 24), then looked for the missing pivot (23), did not find it but found a 27-73 instead which served the same purpose. One could say that the two pincers were "too far apart" and the extension "bridged the gap"
edit 20:43 GMT+2: probably should have called it "generalized xy-wing" like in this thread.
I'll remember the proper names ... (eventually) 
things to do:
- memorize generalized xy-wing
- remember distinction between kite and turbot fish
- find out what a sashimi fish is
- study taxonomy (should I say pathology?) of deadly patterns, notably types 2-4
- ...
- remember to have fun
- ...
- get a life
(now that was getting too pathetic  )
____
edit again 20:51 GMT+2: this is a 刺身 (sashimi ):
| Wikipedia wrote: | | The word sashimi means "pierced body", i.e. "刺身 = sashimi = 刺し = sashi (pierced, stuck) and 身 = mi (body, meat), may derive from the culinary practice of sticking the fish's tail and fin to the slices in identifying the fish being eaten. |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Thu May 01, 2008 8:28 pm Post subject: |
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nataraj,
I believe I can dispatch one of the things on your list quickly: Sashimi Fish.
A Sashimi Fish is essentially a Finned Fish with the piece of the fish by the Fin missing (cut away, so to speak). In a standard Finned Fish, the Fin shares a box with part of the potential Fish, with eliminations occuring in the same box. However, the elimination is still valid even if the involved candidate digit is missing from the cell(s) in the Fin's box belonging to the Fish.
| Code: | +-------+-------+-------+
| v . . | . . . | . . . |
| v . . | . . . | . . . |
| 2 2 2 | . 2 . | . . . |
+-------+-------+-------+
| 2 . . | . . . | 2 . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| 2 . . | . 2 . | 2 . . |
+-------+-------+-------+
Finned Swordfish, Fin = r3c23
+-------+-------+-------+
| v . . | . . . | . . . |
| v . . | . . . | . . . |
| . 2 2 | . 2 . | . . . |
+-------+-------+-------+
| 2 . . | . . . | 2 . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| 2 . . | . 2 . | 2 . . |
+-------+-------+-------+
Sashimi Swordfish, Fin = r3c23 |
A Skyscraper canned by viewed (in an overkill sort of way) as a pair of "Sashimi X-Wings." However, if you make one of those Fins 2 cells, then Sashimi X-Wing becomes a good way to describe it:
| Code: | +-------+-------+-------+
| v . . | . . . | . . . |
| v . . | . . . | . . . |
| . 2 2 | . 2 . | . . . |
+-------+-------+-------+
| 2 . . | . 2 . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
Sashimi X-Wing, Fin = r3c23 |
[It could also be described as "grouped (multi-)coloring."] |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Thu May 01, 2008 10:15 pm Post subject: |
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| Asellus wrote: | | [It could also be described as "grouped multi-)coloring."] |
Yes, i always see it as grouped sykscraper.
Nataraj,
my way to look for extended/generalized xy-wings is opposite. Dont see the pincers first, but look for bivalue cells with a common digit in a unit, which can work like an xy-wing pivot.
Looking at your post, good stuff, i think  |
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Victor
Joined: 29 Sep 2005
Posts: 207
Location: NI
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| Posted: Thu May 01, 2008 11:45 pm Post subject: |
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| Quote: | | .. remember distinction between kite and turbot fish |
Please let me know what a turbot fish is and the difference between turbot fish, x-cycles & fishy cycles (if any) as well, if you know that.
Sorry to be finicky, but | Quote: | | W-wing is an xy-chain with 4 cells. |
isn't quite right: many are but not all, for a true XY-chain is composed of bivalue cells, whereas a W-wing merely needs the two 'base' numbers to be conjugate, whether they're in bivalue cells or not. |
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ravel
Joined: 21 Apr 2006
Posts: 536
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| Posted: Fri May 02, 2008 11:05 am Post subject: |
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| Victor wrote: | | Quote: | | .. remember distinction between kite and turbot fish |
Please let me know what a turbot fish is and the difference between turbot fish, x-cycles & fishy cycles (if any) as well, if you know that. |
See the original turbot fish thread by Nick70 here (an ancient post). You can see that the 4 turbot fish patterns include the candidate(s), that can be eliminated. The same eliminations can be made by using 2 of the strong links (kites or skyscrapers) in the patterns. The first pattern is also an x-cycle B=C-D=E-A=B, meaning B must be true. |
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cgordon
Joined: 04 May 2007
Posts: 769
Location: ontario, canada
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| Posted: Fri May 02, 2008 3:21 pm Post subject: |
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I solved the first one using all manner of clever stuff but in the end I wasn't convinced that I couldn't have persevered using basics alone. I found lots of ERs with <4>s and an xyz wing for <123>
Some of these forums are starting to look more like Sushi menus. |
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Victor
Joined: 29 Sep 2005
Posts: 207
Location: NI
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| Posted: Sat May 03, 2008 8:39 am Post subject: |
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Ravel: | Quote: | | See the original turbot fish thread by Nick70 here (an ancient post). |
I think I had read it and somewhat ignored it - I'd certainly forgotten it if I had read it. As you say, most of them can be seen as 4-pointed things (kites/skyscrapers) rather then 5-pointed things with a weak discontinuity.
(Each to her/his own taste I guess, but I prefer to think of skyscrapers in particular as 4-pointed, becasue you can often do more than one elimination, whereas if you think of it as a 5-pointed turbot fish you may have to repeat that to do the other elimination(s).)
I think I'd recognise the kind where there's a strong discontinuity, fixing the number in that cell, but I don't recall ever seeing one.
Anyway, thanks: in summary, a turbot fish seems to be defined as a 5-point x-cycle loop with (necessarily) a discontinuity: if it's a weak discontinuity it's what most of us call a kite/skyscraper. |
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