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polle ,

I don’t know what a palindrome is, it looks like iam better off this way.

gerbler ,

A word, number or string that can be read the same backwards and forwards. Like 2112, 11/11/11, “A Toyotas a Toyota”, “Was it a cat I saw?”.

Emmie ,

Let us substitute: ( - x, ) - y
Thus ()() becomes xyxy
())( becomes xyyx
Now clearly it can be seen, even while high, that the second one is and the first isn’t

JokeDeity ,

Okay, but yes it is if you aren’t being extremely technical and pedantic.

jaybone ,

A palindrome is about symbols. Not the visual representation of those symbols.

TriflingToad ,

for those too lazy to google,
palindrome /păl′ĭn-drōm″/ noun A word, verse, or sentence, that is the same when read backward or forward. “madam; Hannah; or Lewd did I live, & evil I did dwel.”

() () backwards is )( )(
() )( backwards is () )(

Kaelygon ,
@Kaelygon@lemmy.world avatar

this took me a while but after converting to ascii in hex I get it

“())(” = 40 41 41 40

“()()” = 40 41 40 41

As long your strings aren’t null terminated

pingveno ,

As long your strings aren’t null terminated

What kind of monstrous bug prone language would do that?

Klnsfw ,

Tbh, at first sight I was like “wtf they’re talking about? Is this a regexp or some kind of string formatting? In which language?”

Ahaha I hate you. Have a great day !

ArmokGoB ,

1212 isn’t a palindrome, but 1221 is.

iAvicenna ,
@iAvicenna@lemmy.world avatar

fuck that was unexpected

HowManyNimons ,

Fucking.

Imgonnatrythis ,

This is especially terrible when lying in bed. With a keyboard or pen and paper you can make sense of it, it hurts my brain a bit to visualize it though.

parapsyker ,

This has ruined my day.

CanadaPlus , (edited )

Calm down, everyone. Brackets form a tree structure, and can be represented by a free magma, while strings with concatenation are equivalent to a free monoid. You’re essentially asking for the two respective common involutory operations to be connected by this map, just because they’re involutory, which put that way is a wild guess at best. In fact, reversing this string produces something outside the range of the map entirely, which is injective and so can’t be surjective for combinatorical reasons.

… Yeah I might be the only person that finds that useful.

schnurrito ,

yeah but that’s just like your opinion man

CanadaPlus ,

I mean,the part about the “wild” guess is, but this is a counterexample, and something like the reciprocal vs the negative of reals or rationals when moved across the log map would be an example. So, either you’re a galaxybrain that just instantly knows if the transformation is structure-preserving in that way, or you’re guessing to some degree as well.

The symbols and abstractions have touched me in no-no ways. I miss okaybuddyphd on r*ddit, they knew the pain.

I suppose I could also just say that characters which aren’t just drawn asymmetrical, but actually point in a direction as part of their function, look wrong when reversed like this. So, (e) -> )e( is no good, but bed -> deb is fine.

AFaithfulNihilist ,
@AFaithfulNihilist@lemmy.world avatar

https://lemmy.world/pictrs/image/4811b8a8-60ca-40cd-b80b-1a49b97aeaae.gif

I’m just going to assume those 4 dollar words are real and you aren’t just misspelling normal words to fuck with us.

Non surjective free magma? What about the doblastic amortized basalt?

CanadaPlus ,

I was saying unipotent at first instead of involutory, which was actually the wrong jargon because of the context, but I’ve fixed that now. Yes, they’re all real.

A glossary:

Involution

Surjective

Injective

Free magma

Free monoid

Map, although in this context I could probably have just said function. I go with map by default when thinking bidirectionally.

I think most people here will know combinatorics, the study of the different possible configurations of something. The number of n-length strings with two possible characters is 2^n^, as coders should all know, and the number of trees turns out to be Catalan’s numbers, many of which have prime factors other than 2. This is an injective map from n node trees to 2n character strings, so it’s possible, but you’ll (almost?) never get a perfect match, so by the pigeonhole principle it can’t be surjective.

I’m wondering now if Catalan numbers are O(n!). The equation has a lot of n! but it also has a certain smell like it might depend on big or little o.

AFaithfulNihilist ,
@AFaithfulNihilist@lemmy.world avatar

You are awesome.

Lemmy is better for you being here. Thanks for the reading material!

CanadaPlus ,

You’re very welcome! How kind.

istoff ,

Best palindrome I ever come across is boob. I heard Jimmy Carr say it, but he could be repeating somebody else’s joke.

radicalautonomy ,
@radicalautonomy@lemmy.world avatar

dood

istoff ,

Had to take a break and come back later before it made sense.

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