I previously posted this in the wrong section, so I have moved it to here. See below a Finned Jellyfish of the digit 2. Lilac cells indicates the regular jellyfish, the brown cell the fin, the purple cells indicate the digit 2 that would be eliminated if the fin was not a 2. There is a chain leading from the fin to r2c5 which means, whatever the value of the fin the 2 in r2c5 is always eliminated.

2 r9c9 - 2 - r8c7 = 2 = r2c7 > r2c5 <> 2

So, would one of these be an acceptable notation;

[ Finned Jellyfish (2) r1469 c2459 fin r9c9 ] - 2 - r8c7 = 2 = r2c7 > r2c5 <> 2

or, as the digit 2 is already defined in the Jellyfish statement ...

[ Finned Jellyfish (2) r1469 c2459 fin r9c9 ] - r8c7 = 2 = r2c7 > r2c5 <> 2

or, something like;

[ Finned Jellyfish (2) r1469 c2459 fin r9c9 ]: r9c9 - 2 - r8c7 = 2 = r2c7 > r2c5 <> 2

I am just interested to know the correct notation, that will show the chain, leading to a definite conclusion. I am still hoping someone can answer, if there is a term for this type of hybrid fish/chain construct. Please note, I am not interested in other solutions, as you know, there are usually more than one way to skin a cat in sudoku. Thanks in advance.

... edited to make more readable, and correct typo as pointed out by Cenoman