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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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 Posted: Wed May 12, 2010 3:28 pm Post subject: 512 VH A step that needs a name |
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| Code: |
+-------+-------+-------+
| 3 . . | . 1 . | . . . |
| . . . | . 2 6 | . . . |
| . 4 . | 3 7 . | 8 . . |
+-------+-------+-------+
| . 5 6 | . . . | . . 1 |
| . . 2 | . . . | 6 . . |
| 8 . . | . . . | 3 9 . |
+-------+-------+-------+
| . . 7 | . 9 4 | . 1 . |
| . . . | 7 6 . | . . . |
| . . . | . 3 . | . . 9 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site
Here is a one step solution. Does anyone have a name for it? | Quote: | (1)r8c1=r8c6-r6c6=r6c2-r9c2=(1)r8c1; r8c1=1
Looks like a turbot with 2 strong links to a cell |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Wed May 12, 2010 4:27 pm Post subject: |
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I see three guises:
1)A skyscraper on 1s so r5c1 and r9c2 <>1 and so r8c1 must be 1 (Edit:oh yes and skyscraper can also be said to be a specific example of a turbot although the term "skyscraper" appears to be more frequently used these days as,imho, it is more descriptive)
2)An x-cycle on 1s that creates a contradiction. Even if you start r8c1 as <> 1 the chain directs that r8c1 MUST be 1.
3)Needless to say these are both AICs. |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Wed May 12, 2010 5:23 pm Post subject: |
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| Mogulmeister wrote: | 2)An x-cycle on 1s that creates a contradiction. Even if you start r8c1 as <> 1 the chain directs that r8c1 MUST be 1.
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I call it a five sided loop with a contridiction. A turbot and kite are also 5 sided loops with a contridiction. They have at least one weak link at the point of contridiction. This guy has two strong links there making the value in the cell true. He should have a name.....like his brothers turbot, kite and skyscraper. Then he could be a legal VH player.  |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Wed May 12, 2010 5:46 pm Post subject: |
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Its just been an x cycle to me but that's maybe because, as you say, there is no convenient shorthand as yet.
I first encountered "skyscraper" and "2 string kite" at Havard's site - not sure if this one has been catalogued or indeed the converse loop which is a pattern where even if you start with x, the loop implies that the start cell is not x.
Using a "shape" metaphor could be difficult as this type of pattern could have quite a few shape variants.
Also - what then do you call one of these with variation of candidates ? So far we've just looked at single candidate loops.
If they have not already attracted a name (surely they have?) perhaps a "behaviour" metaphor would be a good way to go ?
eg X-ON/X-OFF Loops
If the start cell is NOT x and the loop implies that it IS x then it could be called an X-ON loop.
If the start cell IS x and the loop implies that it is NOT x then it could be called an X-OFF loop.
That or go back to some other metaphor like "Birthday Candle" you know, those ones that relight after you've blown them out.  |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Wed May 12, 2010 5:53 pm Post subject: |
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Alright then back to fish:
Where the removal of candidate x from start cell still results in loop implying that start cell = x ======> Sting Ray (sting in tail)
Where the placing of candidate x in start cell still results in loop implying that start cell <>x Manta Ray (no sting in tail) |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Wed May 12, 2010 6:31 pm Post subject: |
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The shape needs a name?
Hm, chemists might think of an organic molecule, like furan.
At least as common as skyscrapers ... 
If it has to be a building, Pentagon comes to mind
With a little imagination and some mystic touch: Baphomet
----------
Personally, I don't really need a name for every single shape, the term "coloring" or "multi-coloring", or "x-cycle" would be quite sufficent.
Or "discontinuous loop"
Or single candidate AIC.
Or ... |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Wed May 12, 2010 6:50 pm Post subject: |
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| nataraj wrote: | | Personally, I don't really need a name for every single shape, the term "coloring" or "multi-coloring", or "x-cycle" would be quite sufficent. |
Is the term x-cycle limited to just 5 sided cycles? If so x-cycle would be a great way to identify this family of steps.
The problem is identifing the allowable steps in a VH puzzle. Turbots, kites and skyscrapers are OK ... other x-cycles are not.  |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Wed May 12, 2010 6:58 pm Post subject: |
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| arkietech wrote: | If so x-cycle would be a great way to identify this family of steps.
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As suggested Dan, I believe that's what they are called - although i like baphomet!!
(runs for dictionary) |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Wed May 12, 2010 7:01 pm Post subject: |
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| nataraj wrote: |
Personally, I don't really need a name for every single shape, the term "coloring" or "multi-coloring", or "x-cycle" would be quite sufficent.
Or "discontinuous loop"
Or single candidate AIC.
Or ... |
Baphomet ! Great word - but I agree. the shape thing helps when going up the learning curve. |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Wed May 12, 2010 7:06 pm Post subject: |
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| arkietech wrote: |
The problem is identifing the allowable steps in a VH puzzle. Turbots, kites and skyscrapers are OK ... other x-cycles are not. |
Why not?
Who says what is "allowed" and what isn't?
I take the liberty of using any suitable (i.e. useful for ME) technique to solve a given puzzle. The puzzle, on the other hand, does not care what I do, it just is.
The grade "VH" in the context of this site means that the puzzle cannot be solved by "basics" (what does that mean, exactly, and who says so?) but can be solved by x-wing, xy-wing or xyz-wiing. That does not mean it cannot be solved by any other method. |
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Luke451
Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
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| Posted: Wed May 12, 2010 8:37 pm Post subject: |
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If one were to ignore the scraper and use all the cells, I like "discontinuous nice loop" the best. Then you'd have to go with NL notation, of course.
How about some obfuscation just for fun  . ... hey, I gotta fulfill my role around here.
| Code: | *-----------------------------------------------------------*
| 3 26 58 | 4 1 58 | 9 27 267 |
| 57 78 9 | 58 2 6 | 1 3 4 |
| 26 4 1 | 3 7 9 | 8 25 256 |
|-------------------+-------------------+-------------------|
| 79 5 6 | 29 48 3 | 24 2478 1 |
| 179 3 2 | 19 48 #17 | 6 458 58 |
| 8 *17 4 | 6 5 *127 | 3 9 27 |
|-------------------+-------------------+-------------------|
| 256 268 7 | 258 9 4 | 25 1 3 |
|*125 9 3 | 7 6 *125 | 245 248 28 |
| 4 *12 58 | 125 3 #1258 | 7 6 9 |
*-----------------------------------------------------------*
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A five link single digit closed loop is an illegal pattern known as a Broken Wing. In the PM above, one of the hashed cells (the "guardians") has to be a (1). Whichever is true forces (1)r8c1, among other things. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Wed May 12, 2010 9:17 pm Post subject: |
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All I see is that Dan used a discontinuous loop instead of a shorter chain (for the Skyscraper).
(1)r8c1=r8c6-r6c6=r6c2; r5c1,r9c2<>1 |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Thu May 13, 2010 2:35 am Post subject: |
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| daj95376 wrote: | All I see is that Dan used a discontinuous loop instead of a shorter chain (for the Skyscraper).
(1)r8c1=r8c6-r6c6=r6c2; r5c1,r9c2<>1 |
If you like shorter chains:
Baphomet:
(1)r8c6-r6c6=r6c2-r9c2; r8c1=1 |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu May 13, 2010 6:04 am Post subject: |
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So to summarise:
1)A name change might make a move "legal"
2)There are "illegal" moves
I have been away for some time and need to look at forum history but I must say I am with nat on this one. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu May 13, 2010 2:40 pm Post subject: |
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I have a feeling that my first response came across different than intended. So, I'll go back to Dan's original question.
What you have is a discontinuous loop ... and I'm unaware of any of them being give a technique name -- other than something nebulous like X-Chain/X-Cycle when one value is used. |
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arkietech
Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
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| Posted: Thu May 13, 2010 3:08 pm Post subject: |
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| daj95376 wrote: | I have a feeling that my first response came across different than intended. So, I'll go back to Dan's original question.
What you have is a discontinuous loop ... and I'm unaware of any of them being give a technique name -- other than something nebulous like X-Chain/X-Cycle when one value is used. |
Danny, there are 5 sided discontinous loops that have names: turbot, kites, and skyscrapers. One does not have a name...it needs one. |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu May 13, 2010 3:42 pm Post subject: |
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Indeed Danny - that was my response but I think Dan may have a point with the naming thing.
I would also add that there are two types of these as I documented above depending on the loop's behaviour:
1)The x cycle where the loop eliminates the given start digit as per today's May 13th VH (thanks to Dan)
(8)r4c4-r4c9=r9c9-r9c5=r5c5-(8)r4c4 so r4c4 <> 8
| Code: | *--------------------------------------------------*
| 2 6 8 | 5 3 1 | 7 9 4 |
| 3 4 1 | 6 7 9 | 28 28 5 |
| 9 5 7 | 48 2 48 | 3 6 1 |
|----------------+----------------+----------------|
| 6 1 3 |*48 5 7 | 9 248 *28 |
| 5 7 9 | 2 4+8 3 | 48 1 6 |
| 4 8 2 | 1 9 6 | 5 7 3 |
|----------------+----------------+----------------|
| 8 3 6 | 9 1 25 | 24 245 7 |
| 7 2 4 | 3 6 58 | 1 58 9 |
| 1 9 5 | 7 *48 248 | 6 3 *28 |
*--------------------------------------------------*
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2)The x cycle where the loop implies a value that was not given at the start.
This thread - Dan's VH 512
(25-1)r8c1=r8c6-r6c6=r6c2-r9c2=(1)r8c1; r8c1=1
| Code: | *-----------------------------------------------------------*
| 3 26 58 | 4 1 58 | 9 27 267 |
| 57 78 9 | 58 2 6 | 1 3 4 |
| 26 4 1 | 3 7 9 | 8 25 256 |
|-------------------+-------------------+-------------------|
| 79 5 6 | 29 48 3 | 24 2478 1 |
| 179 3 2 | 19 48 17 | 6 458 58 |
| 8 *17 4 | 6 5 *127 | 3 9 27 |
|-------------------+-------------------+-------------------|
| 256 268 7 | 258 9 4 | 25 1 3 |
|*125 9 3 | 7 6 *125 | 245 248 28 |
| 4 *12 58 | 125 3 1258 | 7 6 9 |
*-----------------------------------------------------------*
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One could be a baphomet the second one could be a "metobaph".
[!! Edits due to code problems - my first time using this display method!!] |
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Luke451
Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
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| Posted: Thu May 13, 2010 6:46 pm Post subject: |
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Just my humble 2 cents:
I'm down with all the suggestions for names, very clever stuff.
I'm definitely not down with actually renaming discontinuous loops, especially those superseded by something as basic as a skyscraper.
"Du sublime au ridicule il n'y a qu'un pas." ~ Napoleon |
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Mogulmeister
Joined: 03 May 2007
Posts: 1151
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| Posted: Thu May 13, 2010 7:09 pm Post subject: |
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Fair enough.
However, as Napoleon also said:
C'est l'imagination qui gouverne le genre humain.
One man's xy wing is another man's 3 step xy chain is another man's ALS.
I don't think this is renaming at all - skyscrapers are a type of turbot and both coexist. Also look at the example in May 13 VH (Daily Sudoku) where
skyscraper=# and baphomet = *
| Code: | *--------------------------------------------------*
| 2 6 8 | 5 3 1 | 7 9 4 |
| 3 4 1 | 6 7 9 | 28 28 5 |
| 9 5 7 | 48 2 48 | 3 6 1 |
|----------------+----------------+----------------|
| 6 1 3 |*48 5 7 | 9 248 *28# |
| 5 7 9 | 2 4+8# 3 | 48 1 6 |
| 4 8 2 | 1 9 6 | 5 7 3 |
|----------------+----------------+----------------|
| 8 3 6 | 9 1 25 | 24 245 7 |
| 7 2 4 | 3 6 58 | 1 58 9 |
| 1 9 5 | 7 *48# 248 | 6 3 *28# |
*--------------------------------------------------*
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I suspect this situation is analagous to the 3 hop XY chain = XY-wing. In Danny's example above, the baphomet is in the horizontal plane but the skyscraper on 8s is in columns 5 and 9 (in the vertical plane).
When I was learning this game I was very pattern based and didn't come to discontinuous loops for some time. If it helps with understanding the game better by seeing things in a different way then so much the better imho. I think its a good thing. |
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