The New Sudoku Players' Forum

[SpAce]

For a UFG fish with the ideals it carries, it was always assumed that the eventual eliminations can be eliminated if the fish body were to be true … This ideal has been challenged by this creature and is possibly the main reason behind the rejection.

The fish body was always fundamental in the ideals of the UFG logic. Logic however remains logic no matter what idealists like me say.

I fully agree with everything you say. I don't think a creature with an invalid fish body should be accepted as a fish, even though the logic seemingly works similarly. It leads to misconceptions. A normal finned fish is an almost-pattern with spoilers, where both the pattern (fish body) and the spoilers (fins) are capable of weak links and need to agree on the eliminations. A headless fish is instead a deadly pattern, where the fins are no longer spoilers but guardians, and the fish body can't have any weak links (and thus doesn't even need any connection to the eliminations). Two quite different things.

[Sudtyro2]

Special thx to SpAce and tarek for their extensive commentaries!

I'm not sure exactly where to go from here since I would've tried the following, as suggested earlier, but now also including a link to the current discussion:
Headless Kraken (1)C3\r1 + rfr6c3 + fr3c3 => -1 r1c1; stte.

However...

A headless fish is instead a deadly pattern, where the fins are no longer spoilers but guardians...

Would you mind showing me exactly how you would present that DP, its guardians, and the eventual elimination in this case?

SteveC

[SpAce]

Hi Steve,

A headless fish is instead a deadly pattern, where the fins are no longer spoilers but guardians...

Would you mind showing me exactly how you would present that DP, its guardians, and the eventual elimination in this case?

I thought I already did in my first post. I just used a generic name "Illegal fish" but you could of course specify it as the Headless kind:

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Headless Cyclopsfish (1)C3\r1 with two guardians (1r3c36):

(1)r3c3 == (1-9)r6c3 = r9c3 - (9=1)r9c8 - r9c5 = (1)r1c5 => -1 r1c1,r3c6; stte

Like a normal DP, the headless (or other illegal) fish acts as a catalyst for the derived strong link between the guardians. It has no other job, so it doesn't show up in the chain (unlike a valid fish body which must be included in the same SIS). Also, because it's not a real fish, the term "Kraken" should not be used here (unless it's a kraken type of chain; i.e. the term changes meanings). Btw, I wonder who had the bright idea of giving that term two different meanings It should have been reserved for fishes only.

Of course none of this makes any practical sense with headless 1-fishes, because the guardians have a native strong link and we could drop the DP complication. (The same is true for any valid finned 1-fish too: the fish complication adds no value because the fish and the fins are natively linked. The principles are valid for any fish size, though, so there's nothing wrong with it either. I play along because you like to use 1-fishes for some reason. However, the exercise would be more interesting with actually useful fish sizes.)

How about connecting two remote-finned 1-fishes:

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Kraken Franken Cyclopsfish (1)C3\b1+rf:r6c3; Kraken Cyclopsfish (1)C5\r1+rf:r9c5

(1)C3\b1 = (1-9)r6c3 = r9c3 - (9=1)r9c8 - r9c5 = (1)C5\r1 => -1 r1c1; stte

The chain proves that the remote fins of the two fishes have a derived weak link, so they can't both be true -- which means that at least one of the fishes must be true (ie. they have a derived strong link). The same works with different cover sets, of course:

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Kraken Cyclopsfish (1)C3\r3+rf:r6c3; Kraken Franken Cyclopsfish (1)C5\b2+rf:r9c5

(1)C3\r3 = (1-9)r6c3 = r9c3 - (9=1)r9c8 - r9c5 = (1)C5\b2 => -1 r6c3; stte

With a bit more exotic fish we could avoid fins and chains altogether:

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Siamese Alien Jellyfish (Rank 1):

{19C3 1C5 9N8} \ {19r9 6n3 1r1b1|1r3b2} => -1 r1c1,r6c3; stte

[Sudtyro2]

Once again, special thanks are due to both SpAce and tarek for their helpful feedback.

It is now very clear to me that the "Sashimi 1-Fish" as first posted by DAJ is, in fact, not a true 1-Fish per UFG guidelines. That means only two of my lead post 1-Fish were actually caught with the same worm. However, I do still like the true 1-Fish concept used there since it's definitely more fun than simply solving the Kraken column (1)r36c3. My dozen or so past Sashimi 1-Fish postings will be suitably edited [9/8/19] to cite these discussions.

SteveC