Name this Turbot Fish type!

Advanced methods and approaches for solving Sudoku puzzles

Re: Name this Turbot Fish type!

blue wrote:
(...) you'll see it together with the normal ERs.

You mean "grouped" ERs ?

Yes, but in the case of ERs, "grouped" is the normal, and ungrouped is the abnormal That's one reason why we have this predicament.

If you want a new name to catch on, i think you should find one with three syl-la-bles.
Two-String-Kite, Sky-scra-per ... Some-thing-else.
Tur-bot-Fish ... hmm ... I think I see a pattern

Nice catch!! You clearly have superior pattern recognition skills! How about my second option: Turbot Crane? That has three syllables, doesn't it? (And like the 2-String Kite, its official name could be shortened in use.) I'm open to better suggestions, too.

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

SpAce wrote:
blue wrote:
(...) you'll see it together with the normal ERs.

You mean "grouped" ERs ?

Yes, but in the case of ERs, "grouped" is the normal, and ungrouped is the abnormal That's one reason why we have this predicament.

Totally understood !

How about my second option: Turbot Crane? (...)

Love it !
blue

Posts: 894
Joined: 11 March 2013

Re: Name this Turbot Fish type!

Some do, some teach, the rest look it up.

StrmCkr

Posts: 1178
Joined: 05 September 2006

Re: Name this Turbot Fish type!

StrmCkr wrote:

looks pretty similar to the shape.

True! Then the grouped variant, i.e. the "normal" ER with its square angles, could be called Tower Crane!

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

StrmCkr wrote:so yes simple coloring is actually single digit pattern coloring another way of saying an x-cylce/ or x-chain.

No, it's not, unless you have a weird definition of Simple Coloring. In every definition I've seen it only uses conjugate clusters, so it's not capable of finding all eliminations X-Chains (or even simple Turbots) do. You need Multi-Coloring or X-Coloring to match X-Chain capabilities when weak links must be crossed (i.e. most of the time). Besides, I see any coloring as a solving technique, not a descriptive and documentable pattern (like chains or fishes are).   It's funny, though, that back in the day when Turbots and its subtypes were introduced, some people seem to have objected because they also thought Simple Coloring would do the same tricks. It doesn't, unless everything is conjugate-linked. Then again, it also appears that Nick70, who introduced Turbot Fish, didn't originally realize weak links even could be used in his patterns (but corrected it later when he did).

the point i am making is that "patterns" single digit solving methods eventually became the UFG and these are not classed as chains. {to repeat for a third time as it was clearly missed in previous posts}

Ok. I guess I might be catching your point finally. So you're saying that Skyscrapers and Kites were originally intended as "patterns" and not chains? Well, I don't see the difference, because they're clearly chain patterns. More importantly, I also don't think there's anything in Havard's original post indicating that he didn't see his patterns as chains (and unlike Nick70, he knew from the start where the strong and weak links needed to be for each type).

Hodoku, however, seems to view Skyscrapers and Kites as some special "patterns", because it doesn't display chaining links with them (unless viewed as Turbots or X-Chains). That's pretty annoying because it's less readable, and doesn't make sense anyway.

the names skyscraper, Empty Rectangle, 2-string kite was applied to a pattern based solving method. {reference to Harvard opening words}

Sure, he used the word "pattern", but all patterns are based on some logic and the simplest way to explain his is chaining logic. I don't see anything indicating that Havard saw them as any other kind of patterns. The only other possibility is fish patterns, but I don't think such complicated fishes had even been invented by that time (2005). Seeing them as fishes is clearly a later discovery, as the required Frankens and Mutants were discovered in 2006 and as a result the UFG was created that year. Thus Havard must have seen his patterns through chaining logic (even if lacking current chaining notations).

not specific cases of Turbots.

I don't agree. Havard said he had discovered those patterns independently before finding out about Turbots, but when he did, he smartly realized they were subtypes of Turbots and presented them as such from the get-go. I think it's very clear in his opening post. (Besides, even if he hadn't, I don't see how it would make any difference -- his patterns ARE subtypes of Turbots, and that's all I care about. What the inventor originally intended years ago is not really relevant at this point, since we probably have a more complete picture of the logical categories and relationships now. But, it seems that Havard had the right idea from the start, so it's even simpler.)

it was noted that they could be considered part of the Turbot chain family and Harvard added it to his opening post. which we both posted.

I don't agree. It seems to me that he had noticed that relationship before he posted and mentioned it right away himself, so it was not a later addition. No one had to tell him his patterns were Turbots, but some still did because they thought he didn't understand. Understandably he got a bit annoyed and replied:

Havard wrote:I discovered these patterns long before I knew anything about the Turbot Fish. However after I discovered that they were already covered by the definition of Turbot Fish, I have made sure to say this in every post I have made. Hence I don't understand your need to point this out again?

Can you accept his own words?

to me every time those names show up they aren't "turbo chains" they are actually from the U.F.G

That's fine, but I bet your POV is pretty unique. However, one fact you can't deny (I think) is that 2005 was before 2006. Right?

so the mistake to me is associating those names with
Turbots which is a length 4 - x cycle which happens to make size 2 ufg fish.

I don't see the same mistake -- neither logically nor historically. I think it's clear that Havard fully understood and accepted his patterns as subtypes of Turbots and saw them as chains. The fish POV of those patterns came later, and I bet it has only academic importance to most people. You're of course free to use whatever POV you like!

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

So, which name should we choose? I think blue's brilliant observation about the three syllables became an immediate requirement, so the plain "Crane" is out (although could be used as a nickname). I think StrmCkr's "Loader Crane" is quite awesome, as it's not only close but it is the pattern shape. Unless someone has even better ideas, I'm ready to back that one. Then the name would also have three contributors, which would rhyme well with three syllables

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

Havard wrote:
I discovered these patterns long before I knew anything about the Turbot Fish.
yup i do see it plain as day, "pattern" first. then noticing it could be described as chain type post facto and mentioned it with in the same post

my point of view is that pattern techniques eventually landed collectively in one spot and became known as "fish" within the ufg:

could he see it both as a pattern and a chain:
yup he definitely did that part is clear as he lists it as that it can seen as a turbot.

did he find it as a pattern first? more then likely given that most of his posts are within the early forums of pattern solving in 2005/2006. { he also states that he seen it first as a pattern.}

The only other possibility is fish patterns, but I don't think such complicated fishes had even been invented by that time (2005).

the most complicated fish in those days was all Row/Col based ie "finned" sword fish, jellies, squirm-bag{Starfish} that was 2005 on the programmers forum.
{ before the inclusion of box type was accepted. ER's and hinges opened that door. }

his patterns ARE subtypes of Turbots, and that's all I care about.
yup, and we can argue what he was thinking with no real definitive outcome. {with out him responding} either way we are stuck at a point in time where Turbots and Size 2 UFG share names, with no real reason as to why, {we both can see either side of the coin. }

I'm willing to let the that side of the topic go moot as we are both right and wrong an no real way of sorting out which it is.

I get you want closure on the minimal ER class with a fixed name: "Loader Crane" works for me, i can accept that as it looks like one & still contains "ER" part for historical name keeping.

it's not, unless you have a weird definition of Simple Coloring. In every definition I've seen it only uses conjugate clusters,

grouped strong links and conjugate links. and weak inferences at sector changes

pretty much where Simple Sudoku was at in development, before it was no longer worked on. { he was adding grouped and box links to incorporate ER's }
{i do not remember where i was reading that from back in the day either here or the programs forum}

however
you won't see much documentation on simple coloring using [xxx | . . . | . x . ] style links
for a reference starting point
http://forum.enjoysudoku.com/simple-colouring-and-grouping-of-candidates-t2954.html
http://sudoku.com.au/sudokutips.aspx?Go=D17-2-1994
Some do, some teach, the rest look it up.

StrmCkr

Posts: 1178
Joined: 05 September 2006

Re: Name this Turbot Fish type!

StrmCkr wrote:
The only other possibility is fish patterns, but I don't think such complicated fishes had even been invented by that time (2005).

the most complicated fish in those days was all Row/Col based ie "finned" sword fish, jellies, squirm-bag{Starfish} that was 2005 on the programmers forum.
{ before the inclusion of box type was accepted. ER's and hinges opened that door. }

All of the strange fish came after Jan 2006 including this:
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`Fish with 18 eliminations including 4 cannibalistic.........75.13....29.87.............41.7..82.87..5.93..........5..3..78.38.92.51.After 3 finned swordfish.--------------------.--------------------------.----------------------------.| 16   346   134-68  |  2456   469      245-69  |  1234-6   45-679   1235789 || 7    5    *468     |  1      3       *2469    | *246     *469     *24-689  || 2    9    *1346    |  8      7       *456     | *1346    *456     *1345-6  |:--------------------+--------------------------+----------------------------:| 69   236   235-69  |  24-6   14-689   123489  |  146      4567     145-67  || 4    1    *3569    |  7     *69      *3-69    |  8        2       *56      || 8    7    *26      | *246    5       *124-6   |  9        3       *146     |:--------------------+--------------------------+----------------------------:| 169  246   124-679 |  456    1468     145-678 |  2346     469      234-69  || 5    246   124-69  |  3      146      14-6    |  7        8        24-69   || 3    8    *467     |  9      2       *467     |  5        1       *46      |'--------------------'--------------------------'----------------------------'Franken Squirmbag: 6 r23569 c369b35 => r1c3678,r23478c9,r4c345,r5678c6,r78c3<>6V(17) XF(00) NF(00) EE(18) CE(04) PE(18)`

tarek

tarek

Posts: 3745
Joined: 05 January 2006

Re: Name this Turbot Fish type!

tarek wrote:
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`Fish with 18 eliminations including 4 cannibalisticFranken Squirmbag: 6 r23569 c369b35 => r1c3678,r23478c9,r4c345,r5678c6,r78c3<>6`

Wow! That's a very interesting specimen. It leads to an off-topic open question I've had about fishes for a while.

How large nxn fishes of each type (shape, fins) do we need to check to find all possible fish eliminations? Or perhaps the inverse is easier: what fish types definitely don't need to be checked for sizes > 4 (i.e. there's always an equally powerful smaller fish available)? I know that limit covers finless basic fishes, and I guess at least some finned basic fishes too, but is there an exact rule about the latter ones? I would guess that the number of fin cells and their locations play a part.

What about Frankens and Mutants? This Franken 5-fish has no fins of any kind, yet it's apparently the smallest one available for those massive eliminations (larger fishes available too for the same). Does that mean there's no size limit for Frankens and Mutants even when they have no fins, i.e. we might have to check up to size 7 to find all possible eliminations? (A related and probably very stupid question: is size 7 the hard ceiling or could there be a useful 8-fish in any configuration even theoretically?)

I know these things have been conjectured and investigated, but I don't remember seeing definite results collected in one place. If they can be found in the UFG or elsewhere, I'd appreciate links to the pages.

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

StrmCkr wrote:yup i do see it plain as day, "pattern" first. then noticing it could be described as chain type post facto and mentioned it with in the same post

my point of view is that pattern techniques eventually landed collectively in one spot and became known as "fish" within the ufg:

could he see it both as a pattern and a chain:
yup he definitely did that part is clear as he lists it as that it can seen as a turbot.

did he find it as a pattern first? more then likely given that most of his posts are within the early forums of pattern solving in 2005/2006. { he also states that he seen it first as a pattern.}

For any of that to make sense, you'd have to define what you mean by "pattern" and how its internal logic is different from a chain (or coloring) in this case. Like I said, I find it unlikely he saw his patterns as fishes, so what other kind of single-digit logic is left? I guess one more possibility is a templates/POM type of approach. It's also very trivial in this case (only two possibilities how the candidates can be placed within each pattern), but for the same reason it's not actually different from the chaining logic at all. Havard also talked about conjugate links etc, which points to chaining logic as well (definitely not fish logic).

Anyway... what do you really mean by "pattern" and "pattern techniques"? I'm sensing that we're using different definitions again, which makes this harder than it should be.

SpAce wrote:his patterns ARE subtypes of Turbots, and that's all I care about.

yup, and we can argue what he was thinking with no real definitive outcome. {with out him responding} either way we are stuck at a point in time where Turbots and Size 2 UFG share names, with no real reason as to why, {we both can see either side of the coin. }

Well, I guess tarek would know something about the UFG part. I've always assumed that they weren't really meant as names for those fishes but to show how those fishes (with their real fish names) were equivalent to the named Turbots:

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` *  X  * |  .  .  . |  .  *  .        /  X  / |  .  .  . |  .  /  .  X  /  X |  /  /  / |  /  X  /        X *X  X |  *  *  * |  *  X  *  *  X  * |  .  .  . |  .  *  .        /  X  / |  .  .  . |  .  /  . ---------+----------+----------      ---------+----------+----------  .  /  . |  .  .  . |  .  *  .        .  *  . |  .  .  . |  .  /  .  .  /  . |  .  .  . |  .  *  .        .  *  . |  .  .  . |  .  /  .  .  /  . |  .  .  . |  .  *  .        .  *  . |  .  .  . |  .  /  . ---------+----------+----------      ---------+----------+----------  .  /  . |  .  .  . |  .  *  .        .  *  . |  .  .  . |  .  /  .  .  #  . |  .  .  . |  . **  .        . **  . |  .  .  . |  .  #  .  .  /  . |  .  .  . |  .  *  .        .  *  . |  .  .  . |  .  /  . Fig 2C: rc\cb                         Fig 2C inverse: cb\rc rc\rb transpose                      rb\rc transpose turbot fish (2-stringed kite)        turbot fish (ER + conjugate link) sashimi mutant x-wing`

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` *  X  * | .  .  . | .  /  .          /  X  / | .  .  . | .  *  . **  X ** | .  .  . | .  #  .          #  X  # | .  .  . | . **  .  *  X  * | .  .  . | .  /  .          /  X  / | .  .  . | .  *  . ---------+---------+---------        ---------+---------+---------  .  /  . | .  .  . | .  /  .          .  *  . | .  .  . | .  *  .  .  /  . | .  .  . | .  /  .          .  *  . | .  .  . | .  *  .  .  /  . | .  .  . | .  /  .          .  *  . | .  .  . | .  *  . ---------+---------+---------        ---------+---------+---------  .  /  . | .  .  . | .  /  .          .  *  . | .  .  . | .  *  .  *  X  * | *  *  * | *  X  *          /  X  / | /  /  / | /  X  /  .  /  . | .  .  . | .  /  .          .  *  . | .  .  . | .  *  .  Fig 2D: cc\rb                        Fig 2D inverse: rb\cc rr\cb transpose                      cb\rr transpose turbot fish (skyscraper)             turbot fish (ER + conjugate link) sashimi mutant x-wing`

I interpret that so that if you want to see them as fishes, you should call them "(Finned) Sashimi Mutant X-Wings" etc, instead of using the short names related to the Turbot Fish family (which imply the chain POV, imho). Perhaps that's not what was intended, but I think it's more logical than the alternative, because Turbot Fishes weren't originally fishes (despite the confusing name). Of course it doesn't really matter what you call them, because both POVs yield the same eliminations using just different logic.

Btw, now that I look at those... isn't the "ER + conjugate link" a bit wrong? Should be just ER (or ERI + conjugate link, but that's unnecessarily complicated), right? That's actually a perfect example of the confusing nature of the ER vs ERI I mentioned earlier! (But hey, soon there's a better option to name those patterns anyway )

About Simple Coloring: as I suspected, we're clearly using different definitions. I can't say your larger definition is wrong, but I don't think it's widely accepted. I also think it's clearer to keep Simple Coloring limited to simple conjugate links only, and use other names for more powerful coloring techniques. Otherwise, what's simple about it anymore (except that it uses single digits)? The same thing with 3D-Medusa: I would only use that name for a multi-digit cluster with simple conjugate links only. For anything more complicated there's GEM.

[Edit: added link to the UFG (i.e. source of the diagrams)]
Last edited by SpAce on Fri Nov 16, 2018 3:12 am, edited 1 time in total.

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

StrmCkr wrote:I get you want closure on the minimal ER class with a fixed name: "Loader Crane" works for me, i can accept that as it looks like one & still contains "ER" part for historical name keeping.

Excellent! Btw, I completely missed that ER part in the name -- that's a brilliant bonus!

In fact, should we make the connection explicit: LoadER Crane? Or is that stupid? Edit: After pondering this a bit more, I think my answer to that question is: Yes, it's stupid. Let's keep it simple. Loader Crane is neater and catchier, and it's actually more logical too, because the lower-case "er" symbolizes a minimal ER. Few people ever saw the pattern as an ER in the first place, so there's no need to emphasize it now either.

Incidentally the capitalization might work better for what I suggested (a bit tongue in the cheek) for the grouped version:
TowER Crane. In this case the capitalization actually makes more sense, because it's the "normal" ER and the connection is important. I doubt anyone will ever use that name anyway (and I'm not sure if it's even a good idea, considering the well-established nature of ER), but for completeness and consistency I might like to have that as an option. I do think something like that would have been a much better name for the pattern in the first place, because it depicts the shape of the full pattern and not just a small part of it, which constantly causes confusion between the concepts of ER and ERI (just look at the example I found in the UFG, one post up).

SpAce

Posts: 2583
Joined: 22 May 2017

Re: Name this Turbot Fish type!

How large nxn fishes of each type (shape, fins) do we need to check to find all possible fish eliminations?

the largest fish with no smaller eliminations is a 7x7+1 { in nxn notation} [ found to date.]
1) 7x7+1 Base: R1458C9B27, Cover: R2C234589B8 Bi{Cells}: 5,73, Exclusions: 77,

Code: Select all
`+---------------+-------------------+---------------------+| 6   78   2    | 3     478    9    | 1     5       478   || 17  3    18   | 2     4578   578  | 789   489     6     || 9   5    4    | 78    1      6    | 278   3       278   |+---------------+-------------------+---------------------+| 2   6    789  | 5     789    4    | 3     789     1     || 4   1    789  | 6789  2      3    | 5     6789    789   || 5   789  3    | 1     6789   78   | 2789  246789  24789 |+---------------+-------------------+---------------------+| 3   79   679  | 4     6789   2    | 789   1       5     || 8   4    15   | 79    3      15   | 6     279     279   || 17  2    1569 | 6789  56789  1578 | 4     789     3     |+---------------+-------------------+---------------------+`

http://forum.enjoysudoku.com/post229153.html#p229153

my nxn+ k fish that replicates nxn fish with no reuse age of sectors has found fish up to size 9x9+2 but all of them had a smaller fish for the same elimination.

nxn+k fish that reuse sectors can scale well beyond those size and has solved a few of the "no fish" grids.

most large fish past size 4 have an equivalent smaller fish.
{ just like subsets ie hidden set of size 4 has a complementary size 5 naked set}
- which is why we don't use quintuplets or larger subsets.

now if some one can prove the smaller size elimination that should in theory exists then fish searching wouldn't be so difficult.
as building base ((1 ->7 ) out of 27) sectors and cover (( 1 -> 7 ) out of 20 )+ ( (0 -> 2) out of 13 ) sectors = millions of fish to check for each digits 1-9.
{around 3 -1/2 hours for all of them on my solver that doesn't use template short cuts like hodoku and that time frame took me 5 years and many revisions to drop down from 16+ hours on 1 cycle. }

fact, should we make the connection explicit: LoadER Crane ? Or is that stupid?
nope, that was what i was hinting at with the ER separated.

For any of that to make sense, you'd have to define what you mean by "pattern" and how its internal logic is different from a chain (or coloring) in this case.

this one will be tricky to explain but ill attempt. patterns understood conjugated cells in a different light cells in a sector both could be true but not both. so, we built patterns around that idea.
that a sector is locked to holding a truth.

what happens if a is true and b is off, using line of sight we add another sector with the same concept

Code: Select all
`on/off     <->    on/off   ||                   || on/off     <->    on/off `

|| indicates 2 way arrows between the "Col" not the normal "strong link"

this example uses 4 cells with 4 way on/off { x-wing}

step 3 would be to evaluate the out come of each of the on/off sequences using line of sight and note the cells that see the "on" cell.
if any cell would see "on" for all the out comes of the cells selected then it would always be off.

this can be done with out needing or understanding "weak links" or even writing yes/no or using colors

Code: Select all
` this one has 3 way on/off  in 5 cells thus all cells aren't on/off directly. the above check proves the eliminations thus the pattern sound {finned x-wing} on/off     <->     on/off ||on/off     <->    (on/off)  ( on/off)  (on/off)  `

loose rules to explain that system: {i don't technically have rules this is made up right here} as all i needed was if any cell would see "on" for all the out comes of the cells selected then it would always be off.

rule 1: any set of sectors with the same number yes/no relation ships then any cell that sees 2 yes's is always off
rule 2: any set of sectors with less then the same number yes/no relationships then any cell that sees all of the yes/no's that aren't line of sight connected must be false.

eventually i figured out how to use
(cell count = row count) as a truth. { 2 cells}
cell count of an intersections ( {Box * Row } + (Box * Row) = Row ) ie 3 cells in one box/row + 1 cell in another box/row = grouped link. { 3 + 3) or (3 + 2 ) is also possible.

easiest to show in base/cover

which is basically what I've been using since i got on this forum using mathematics limitation of placements. ie SETs {containers} to identify truth holders
{every thing in my solver is coded with that concept including all my "wing" patterns }

if you want you can add fancier words and explain the connections and call it a "chain" i can defiantly see how you would do that and can admit they would be similar to a chain/coloring comparitivly.

Code: Select all
` ERI `
was a label i created for advance chaining purposes to mark the direction / connection point of a node link that changes directions in the box row < = > col

it's easier and more compact to pre identify all the ERI Boxes and connect weak links off that 1 cell instead of 2 separate local groups.

you could list the ERI + Conjugated link but it was never really intended for anything out side of coding

but if you don't know what the ERI stands for it's overly complicates the simple ER which just needs the box + row/col listed that it works out of.

this example show cases how it can makes some stuff easier :
this grid has 4 linked ERi's we could reduce it to a box-style x-wing off the hubs instead of 8 grouped links.
eliminations are fun 2, all 4 hubs are removed, all boxes that see 2 boxes on row/col for that row/col <> digit. { row & Col is keyed to the hubs direction } making look up easy.

{and this is just from fish] the concept could be applied to all "chains" as an easier way to link box grouped nodes.

like this which could also fall under the turbot header as 4 grouped links using ERI's
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`+----------------+------------+----------------+| .    (1)   .   | 1   1   1  | .    (1)   .   || (1)  (-1)  (1) | -1  -1  -1 | (1)  (-1)  (1) || .    (1)   .   | 1   1   1  | .    (1)   .   |+----------------+------------+----------------+| 1    -1    1   | 1   1   1  | 1    -1    1   || 1    -1    1   | 1   1   1  | 1    -1    1   || 1    -1    1   | 1   1   1  | 1    -1    1   |+----------------+------------+----------------+| .    (1)   .   | 1   1   1  | .    (1)   .   || (1)  (-1)  (1) | -1  -1  -1 | (1)  (-1)  (1) || .    (1)   .   | 1   1   1  | .    (1)   .   |+----------------+------------+----------------+`
Some do, some teach, the rest look it up.

StrmCkr

Posts: 1178
Joined: 05 September 2006

Re: Name this Turbot Fish type!

SpAce wrote:
tarek wrote:
Code: Select all
`Fish with 18 eliminations including 4 cannibalisticFranken Squirmbag: 6 r23569 c369b35 => r1c3678,r23478c9,r4c345,r5678c6,r78c3<>6`

Wow! That's a very interesting specimen. It leads to an off-topic open question I've had about fishes for a while.

How large nxn fishes of each type (shape, fins) do we need to check to find all possible fish eliminations? Or perhaps the inverse is easier: what fish types definitely don't need to be checked for sizes > 4 (i.e. there's always an equally powerful smaller fish available)? I know that limit covers finless basic fishes, and I guess at least some finned basic fishes too, but is there an exact rule about the latter ones? I would guess that the number of fin cells and their locations play a part.

What about Frankens and Mutants? This Franken 5-fish has no fins of any kind, yet it's apparently the smallest one available for those massive eliminations (larger fishes available too for the same). Does that mean there's no size limit for Frankens and Mutants even when they have no fins, i.e. we might have to check up to size 7 to find all possible eliminations? (A related and probably very stupid question: is size 7 the hard ceiling or could there be a useful 8-fish in any configuration even theoretically?)

These branching discussions is what I would describe as a moderator's nightmare
I'm still trying to digest some of the latest exchanges but let me comment on the above

if the base sectors are of the same type & not mixed (only rows or only columns) with the same applying for the cover sets then you can map the candidates into sets & therefore look for Locked sets (Naked or Hidden counterpart) If the base or cover sectors are mixed then I don't think that it would be easy to see the counterpart (if there is any).

See Lummox JR's post here:
http://programmers.enjoysudoku.com/www.setbb.com/sudoku/viewtopic783b.html?t=240&mforum=sudoku

If you find a way to map you sectors in a way (transpose/point/...) that shows all 81 cells in a row v column grid style then you have discovered the ultimate fish catcher and you'll find your smallest fish then!!! DG is an easy one that can be mapped v boxes (but that is not vanilla).

tarek

tarek

Posts: 3745
Joined: 05 January 2006

Re: Name this Turbot Fish type!

A follow up to TAREK point.
that post is a refrence to using the 4d space to find subsets/fish etc faster.

RC (81 cells on or off)

Rn (lists digit for each row)
Cn (list digits for each col)
Bn (lists digits for each box)

Which is great for naked sets to get hidden you use a bit flip method to show off spots
Or add these other tools to make it 7d space which is the best area to fish from as fish use hidden markups.

NC (lists rows) )
Nr (lists cols)
Nb (lists position in square)

The other space that aids viewing a grid (12 d space)

Mini - row (Saves row if col inside box has candidates)
Mini - col. (saves col if row inside box has candidates)

R MINI BOX - List box if row holds digits inside box
C MINI box. - list box if col holds digits inside box.

E. R. I (described earlier) (mini r +min c = box where Mr * mc cannot equal mc or Mr )
Some do, some teach, the rest look it up.

StrmCkr

Posts: 1178
Joined: 05 September 2006

Re: Name this Turbot Fish type!

tarek, StrmCkr, thanks for the fishing answers! Fortunately this is my own thread, so side-branches aren't a deadly sin

I've played around a little with those additional spaces both of you mentioned, partly in a quest for the "ultimate fish catcher" tarek mentioned, but haven't really found it terribly useful. I've solved a couple of puzzles using only nr or nc space to prove to myself that it's possible (it's very easy, actually, once you see how the boxes get mapped to the mini-lines). Some subsets, fishes and chains are indeed easier to see in a certain space, but maintaining multiple spaces manually is very laborious, and it doesn't seem to yield anything that would not be possible to see in another space.

I haven't really found that using the nb (or bn) space really helps in manual solving at all (except to search for box-based subsets in a line-format) -- and solving with that view alone would be really hard because the columns no longer line up. Perhaps I've missed some hidden benefit of that point of view? Related to that, I haven't seen an easy way to create an arcilla style mapping to find Franken or Mutant fishes. That would be nice, because the arcilla style works quite nicely for basic fishes (finned or not).

SpAce

Posts: 2583
Joined: 22 May 2017

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