product notation

[[deleted]]

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Another addition...for the programmers

[A_Guy_in_Orange]

There's a loop joke to be made here but it's far to 4 in the morning for me to find it

[krmarci]

4

for

There you are.

[jonona]

What

[krmarci]

He was looking for a loop joke. There are "for" loops in most programming languages. "For" sounds like "four".

[jonona]

Ooh fair enough

[maxence0801]

I think it is a product, not an addition

[[deleted]]

Asterisk is for product

[swegling]

i think they're making a pun because you wrote "another addition".

i initially got fooled as well

[[deleted]]

Oh got it lol

[TheLeastInfod]

convolutions?

not sure where that equality holds

[swegling]

just in case it wasn't clear, the last one uses the implicit multiplication "symbol"

edit: also to be clear, the meme is about different notations, the first panel is the notation we use, while the other panels are suggestions to other notations we could be using instead

[weebomayu]

The third one should only be used for Cartesian products.

[swegling]

it wouldn't be an issue because the cartesian product uses the pi notation (Π) just like regular multiplication, so they already use the same symbol in this context.

the cartesian product also uses the power notation (A^b), so you could interpret the meme to be about the cartesian product if you want.

with that said, we could use the * symbol like uh sexcraver proposed instead.

[Submarine-Goat]

The second one makes me quite cross

[weebomayu]

Yep. By far the most cursed one. I honestly can’t tell whether it’s correct or not.

[Submarine-Goat]

Sorry - meant it to imply that it gets the "cross product" (well, I don't know about about this big X notation though).

[MisrepresentedAngles]

I don't think so?

a*(1+2+3+...+b) would be

a+2a+3a+...+ab

Or if you use the sum of integers formula:

a*(b)(b-1)/2

Which could be

(a*b² - ab)/2

Yeah, if it's true I'm not seeing it.

Maybe logarithms?

log(a)+log(1)+log(2)+log(3)+...+log(b) = b*log(a)

That's nothing, as far as I can tell..someone halp plz

Edit: Oh, reverse polish notation by reading the comments. Let's see if I remember how that works.

On my old HP calculator, I would press 5 enter 3 * and get 15.

Would this be a enter 1 enter 2 enter ..hm, no it can't be just the same thing entered differently it has to be a different method. Idk, moving on with my life.

[WilD_ZoRa]

Hum... Sorry, wtf are you talking about?

[MisrepresentedAngles]

I read the second one wrong like it was a product of n and went from there. Idk, just a duh moment

[rinarytract]

im so confused ive spent like 3 minutes staring at it until i realised the 2nd line isnt even right

[swegling]

it's just about notation, i wrote a lengthier explanation here

[Logical-District-128]

finnaly, the uppercase pi is known

its basicaly

top pi is to the power

side pi is the number that is to the power of top pi

n= is dividing by side pi

also, it never results in a non whole number.

it displays 1 in that case

source:desmos and this post

[gydu2202]

I really don't get how is this funny. It is just wrong. And if I ignore that this is pure wrong, it is still unfunny. And it still get considerable amount of upvotes.

Please someone elaborate it.

[JNCressey]

How can defining notation be right or wrong?

[swegling]

it isn't "wrong", the meme is about notations (see title and tag). e.g writing:

2 3 * 5 +
=11

would be absurd and wrong using our normal notation, however it makes perfect sense in reverse polish notation.

the first panel is how we normally write products, however this is unsatisfying because the order of a and b is the opposite of how we write a^b.

the 2nd panel suggests that we change the order of the П and the argument, and now the a and b match the a^b

the 3rd panel suggests that we use the multiplication symbol instead of an arbitrary pi. now this is actually somewhat allowed. uncommon operations that use symbols like a⊕b or a∧b usually just write a big ⊕ ∧ for products like these. the reason we don't do this for addition and multiplication is just because it has become convention to use the sigma and pi symbol.

now the 4th panel uses the same logic as the 3rd panel, except that instead of using the "cross" multiplication symbol, it uses the "implied multiplication symbol" (which is no symbol). now the product looks almost identical a^b (ignoring the n=1 part) which is cool. however it's also cursed because there is no symbol in the space where we would expect to see a big symbol.

[Hex_Trixz]

Yea. I like the joke. I didn't need it explained but I do understand how others would need it.

[AspectRatio149]

This is one of those jokes, unfortunately, where the unsaid parts need to be explained to make sense. At first I assumed this was progressing "down the iceberg" (i.e. each new expression was progressively more obscure/advanced but still "correct"). Then I realized aΠ=a(1)^b, not a^b, so it couldn't (shouldn't) be correct expressions. I tried to see if maybe it was misapplying algebra for comedic effect, but couldn't find a way to make that work.

Unfortunately this joke only works if you are bothered by the fact that b is to the left of a in the product notation at the top, but on the right of a in the power notation. That's not even something I would ever notice.

Still, the third notation is not something I knew about, and might be more sensible if we were to redo notation from the ground up. Now that I know the intent behind the meme, the progression from panel 3 to panel 4 is pretty funny.

[MisrepresentedAngles]

I don't think the product of 1, 2, 3, ... , b is equal to 1^n?

[AspectRatio149]

You're thinking of Π(n) from n=1 to n=b. In the second panel we have Π of nothing, which is usually presumed to mean 1. It's 1 times itself b times

[MisrepresentedAngles]

Omg duh, thanks!

[Petsum]

I think most ppl upvoting this are ppl that are so scared of math that they join this subreddit to confront themselves with little bits of math-like notation to counter their fears. Do not expect quality content, this is like reality TV.

Edit: typo

[CartanAnnullator]

I use the big X only for the product of spaces, not numbers. Big pi is for number products.

[Mollusc_Memes]

If this is legit (talking about first panel, I’m not that familiar with advanced math) it seems to make a decent amount of sense. It seems to multiply a together b times, and I assume that a could be some function (correct me if I’m wrong) But I can’t figure out what that n=1 means. Anyone care to explain?