12:00 AM
@quartata After all…
Aug 7 at 21:02, by Dennis
@Downgoat 14-16 hrs. I wish I was joking.

Good god

I guess he doesn't teach summer session so probably doesn't have anything to do :P

@quartata only 218 not closed, barely enough

@Lynn And I thought I spent a lot of time here...

Me too

12:06 AM
@AlexA., you're back! :D \o/
were you migrating?

Well, you don't. Now you know. :P

@Downgoat Haha yes, just been very busy

@Sp3000 The first line in the submission. The second one is a test suite.

Oh - there wasn't any input so that wasn't immediately obvious to me

12:13 AM

Almost as fun as trying to figure out if Julia has a set type :P

@Sp3000 hahaha

I prefer not to use adblockers ¯\_(ツ)_/¯

12:16 AM
I know. Hence the >_>.

No site has any idea whether I'm using AdBlock so I get 0 ads anywhere
It's glorious

> Net effect: frame-busting busted. Which might naturally lead you to wonder -- hey buster, can you bust the frame-busting buster? And, if so, where does it end?

Hi; I think answers are allowed to assume a fresh interpreter session (no variables hanging around from 'earlier'), is that right? And if so, is it written anywhere? I can't see anything in the Meta site about "ground rules for answers" or "unwritten rules" or anything related

You shouldn't ever assume a variable already exists
So I think it's safe to always assume you're in a fresh session

@TessellatingHeckler Generally, I think the rule is only that your code needs to be able to run multiple times and still produce the correct output. (This is only relevant for ex. function submissions, not full programs.)

12:19 AM
@TessellatingHeckler That depends. A function submission must be reusable, so if it modifies a global variable, it still has to work if you run it a second time.

Hmm; you shouldn't assume a variable exists. In a language where you can use uninitialized variables to initialize them, you can assume it doesn't already exist?
(as long as your code works if run a second time)

Which language are you referring to? Something like PHP/Perl's barewords?

Yes.
\o/
@AlexA. Had no idea these existed. Thanks!

@Dennis My pleasure :D

<subscript>PowerShell</subscript> :stares at floor:
e.g. $n++ will make it an integer and start it counting from 0 but if$n was already defined as 120 in the shell before you ran your script, it would count from there and ruin your answer

12:28 AM
@AlexA. that's epic
especially this github

@TessellatingHeckler Ah, that's okay if your submission is a full program, but not if it's a function that modifies global state (I don't know how PowerShell works, but if that makes a local variable and the function works when called multiple times in a row, then that's fine).

Fun fact: It took me the good part of four hours to get the illustration for my newest challenge
The LaTeX code:

@Doorknob it's ok, I don't know how it works either :| but assignment to a variable makes it locally scoped, and won't update the global scope unless explicitly asked, so a script could be run again without a fresh shell.
Great
thanks

\documentclass{article}
\usepackage{mathtools}
\newcommand{\cat}{\!{}+{}\!\!\!\!{}+{}\!}
\pagenumbering{gobble}
\begin{document}
\begin{equation*}
\begin{split}
L(87654321)&=L(1\smash{\underbracket[0.5pt]{01001110010111111110110001}_{26}}_2)\\
\rule{0pt}{3ex}&=1\cat L(26)\cat01001110010111111110110001\\
&=1\cat L(1\smash{\underbracket[0.5pt]{1010}_4}_2)\cat01001110010111111110110001\\
\rule{0pt}{3ex}&=1\cat(1\cat L(4)\cat1010)\cat01001110010111111110110001\\
&=1\cat(1\cat L(1\smash{\underbracket[0.5pt]{00}_2}_2)\cat1010)\cat01001110010111111110110001\\

@TessellatingHeckler Yep, that's perfectly valid then. No problem!

12:31 AM
@EᴀsᴛᴇʀʟʏIʀᴋ wait wat is blag

@Downgoat blag?

> You Used Some Less Simple Words
goat
;_;

@Downgoat ?

@ΛεγίωνΜάμμαλϠΨΠʹ Oh. Now I realize you are LegionMammal

@LuisMendo ._.

12:34 AM
@EᴀsᴛᴇʀʟʏIʀᴋ xkcd.com/simplewriter

It's the Greek transliteration

I was actually able to read your username with my rudimentary knowledge of how the different Greek letters are pronounced

@ΛεγίωνΜάμμαλϠΨΠʹ It's so obvious now :-)
@AlexA. Do you know the difference between omega and omicron? I always wondered. Just length?

@LuisMendo oh vs ooh i think?

@LuisMendo Nope. When I say "rudimentary," I mean a handful of letters and a lot of extrapolation and guessing.

12:36 AM
@AlexA. Ok. Same as me then :-) But I have the advantage of being Spanish. It's more similar to Greek :-P

:D
Is it true that a long, long time ago, Spanish was written with the Arabic alphabet?

@AlexA. Hm? Never heard of that. I don't think so. It's true that the Arabs took hold of Spain (or the land that now is Spain) for a good several centuries, and gave us a lot of words
Spanish just evolved from Latin, so it uses Latin letters

Hm, okay.

I'm not a lawyer philologist though

CMC: I am thinking of a partial function 𝑓: ℕ → ℝ. You are to determine this function through asking me for values of 𝑓(𝑛) for individual 𝑛.

12:50 AM
We will need to ask countably infinitely many questions
2
unless you provide the actual domain first :-)

> partial function 𝑓: ℕ → ℝ

I mean the domain of the function that is implicit in the partial function. If I understand correctly, that is
( I had to look up "partial function")

@LuisMendo I'll give 𝑓(𝑛) if it is defined for 𝑛, otherwise I will say that 𝑓(𝑛) is undefined.
@LuisMendo IANAP

@quartata Are you sure?

@ΛεγίωνΜάμμαλϠΨΠʹ Meta-CMC: hey, how did you type math-italic "f" and blackboard bold "N"? Does this chat accept LaTeX?
Testing: $f$

12:57 AM
Nope

@LuisMendo It's called "Unicode"

:-(

If it were MathJax you'd need double dollars, but our chat doesn't support MathJax

@ΛεγίωνΜάμμαλϠΨΠʹ Oh, sure! :-)

@AlexA. Single dollars works too. (I have SE ChatJax as a Chrome extension.)

12:58 AM
@El'endiaStarman Really? They don't work in standard MathJax

In fact I use Unicode often for the "times" symbol ("×"). I don't like using "x" as "times"
@Quill mornring!

Can we get back to the CMC? I like to watch you suffer...

.... why

1:00 AM
@Quill 😘

>:U
4

rude

Who?

@ΛεγίωνΜάμμαλϠΨΠʹ As Luis says, you'd have to ask infinitely many questions...

0

Convert Between American and British English Spellings code-challenge test-battery natural-language In this challenge, you will have to write two programs or functions. One will convert a list of words from their American English spelling to the British English equivalent, and the other to co...

1:07 AM
@LuisMendo him /s

Any suggestions for this? ^^

@Sp3000 not necessarily

Why not? Case in point: A059999 ("What's the next number in the sequence 2, 3, 5, 7, 11?")

I've done this kind of mini-challenge before with a different 𝑓, and eventually it was solved...
@Sp3000 Okay, let's add the restriction that the function can be described in less than 140 characters (which it can)

@Sp3000 The strong law of small numbers in action :-)

1:11 AM
@LuisMendo At least those ones aren't deliberately constructed :P

With that restriction, you'd need at most a large number of datapoints

@ΛεγίωνΜάμμαλϠΨΠʹ I guess I'm just being pedantic about theoretics, but I'll bite: can I get f(n) for n = 0 to 20?

@Sp3000 You'll need one per message ;)

:/ that's just spamming chat now

Oh fine
@Sp3000 𝑓(0) is undefined
@Sp3000 𝑓(1) is undefined
@Sp3000 𝑓(2) is undefined
@Sp3000 𝑓(3) = 0
@Sp3000 𝑓(4) is undefined
@Sp3000 𝑓(5) is undefined
@Sp3000 𝑓(6) = 0
@Sp3000 𝑓(7) is undefined
@Sp3000 𝑓(8) is undefined
@Sp3000 𝑓(9) = 0

1:17 AM
Is ƒ defined piecewise?

@Sp3000 𝑓(10) is undefined
@AlexA. can't say
@Sp3000 𝑓(11) is undefined

Okay... Well clearly it isn't continuous, so there's that

@Sp3000 𝑓(12) is undefined
@Sp3000 𝑓(13) is undefined
@Sp3000 𝑓(14) is undefined
@Sp3000 𝑓(15) is 0

You could just put all these in one multiline message you know... >_>

@Sp3000 𝑓(16) is undefined

1:19 AM
Instead of pinging him a million times and getting yourself rate limited.

(good thing I have sound off)

^
|

Here:
𝑓(17) is undefined
𝑓(18) = 0
𝑓(19) is undefined
𝑓(20) is undefined

1:20 AM
just give it in an array
[0, undefined, 0, ...]

@AlexA. All functions from (a subset of) N to R are continuous.

Well, I asked for individual values, so that's how I'll respond...
(condensed of course)

@Dennis How do you define continuous when N is the domain? What's the metric used?

1:23 AM

(if it helps, it's 44791056*72473451)

@LuisMendo OK, all functions from (a subset of) N with the Euclidean distance to R are continuous.

@Dennis Hm I don't get it. Continuity on N? Unless I'm missing something, it's just vacuous truth?

Can there be a discontinuous function where N is the domain? Can't quite remember how continuity works

@LuisMendo Basically. Any function with a discrete domain is continuous.

1:27 AM
@Sp3000 𝑓(3246162402254256) = (Φ(1/5, 4, 1/82) + Φ(1/5, 4, 5/328) + Φ(1/5, 4, 9/164) + Φ(1/5, 4, 25/328) + Φ(1/5, 4, 4/41) + 5Li₄(1/5))/11574317056, where Φ denotes the Lerch transcendent and Li denotes the polylogarithm function

@Dennis Ah, ok

o_O I have no idea what either of those are

@Sp3000 GIYF

@Sp3000 It works by getting arbitrarily close to a domain point, and seeing if the images are also close to each other. But in N you can't get "arbitrarily close" actually

What if you had a different metric on N? Is that possible?

1:30 AM
@Sp3000 You can choose the metric, yes. That's why I asked Dennis. Some are equivalent, though. But on N, whichever metric used, there is no concept of "getting arbitrarily close", I think
That's why I said the property is vacuously true

@Sp3000 The most intuitive but rigorous definition (imho) of continuity at a point a is that for every sequence x(n) that converges to a, f(x(n)) must converge to f(a). In a discrete space, all convergent sequences are constant, so every function is continuous.

Oh, and before anyone asks, yes, 𝑓 is well-defined

all convergent sequences are constant is "vacuously" put in much nicer and appropriate terms :-)
@ΛεγίωνΜάμμαλϠΨΠʹ What does it mean well-defined? That phrase always gets me confused

@LuisMendo As in, I'm not making up the values as I go along ;)

@LuisMendo For N (with 0), you can define d(n,m) = |1/n - 1/m| if both are positive and d(n, 0) = 1/n. With that metric, 0 is an accumulation point, so discontinuous functions are possible.

1:33 AM
@ΛεγίωνΜάμμαλϠΨΠʹ Ah, ok :-D

@ΛεγίωνΜάμμαλϠΨΠʹ glances at 𝑓(3246162402254256) Are you sure?

@Dennis Yes.

@Dennis Interesting. I had never heard of that metric but yes, it makes sense

It basically maps N to the set {0} u {1/n : n in Z⁺}.

Reminds me of and old question in my first course of Analysis. Given a function f from a subset S of the real numbers to the real numbers; f is differentiable on S. Does that imply f is constant on S?
I think I failed on that one, thus I remember very well :-)

1:40 AM
Usain Bolt just won the men's 100m for the third Olympics in a row :O
9

@HelkaHomba what a surprise

Unrelated question: Are "premium domains" just a way to scam customers out of their hard-earned money or am I missing something?

@Dennis idk, the only domain I have is legionmammal978.github.io

And I got a 2nd socratic. I didn't know that was possible o.O

> This badge can be awarded multiple times.

1:42 AM
@Dennis Probably, if they contain dictionary words/are short and they think they're valuable?

Seems to be a conspiracy then, because the domain I want is premium on multiple websites.

o_O

@HelkaHomba Congratulations! Now you are So-Socratic!
:-P

@ΛεγίωνΜάμμαλϠΨΠʹ 39?
btw @Dennis have you received any donations for TIO?

@Sp3000 𝑓(39) is undefined

1:44 AM
Ah wth, it's just twice the usual price.

@ΛεγίωνΜάμμαλϠΨΠʹ I'm Socrates, not Plato. I teach, I don't learn :P

I was thinking of a polyglot challenge for "Hello, World!" but for actual languages instead (like English, Chinese, French etc.)

@ΛεγίωνΜάμμαλϠΨΠʹ 117 = 3*39?

@Sp3000 𝑓(117) = 2

@LuisMendo I'm scraping by Dennis in gold again at the least \o/ (even if he triples my rep...)

1:46 AM
@ΛεγίωνΜάμμαλϠΨΠʹ 1521 = 39*39?

What's this f function thing?

@Sp3000 𝑓(1521) = -2

@Sp3000 Yeah, quite a few actually. 0.05441845 BTC, 40 EUR and 18.66 USD (after fees).

57 mins ago, by ΛεγίωνΜάμμαλϠΨΠʹ
CMC: I am thinking of a partial function 𝑓: ℕ → ℝ. You are to determine this function through asking me for values of 𝑓(𝑛) for individual 𝑛.

@Dennis Huh, none for 0.00021845 BTC?

1:47 AM
OK... I'm more confused now...
What's N and R?

@Sp3000 Those are probably totals

@ΛεγίωνΜάμμαλϠΨΠʹ 254560185 = 12543*20295?

@Sp3000 That's the total. I received three individual BTC donations.

@ΛεγίωνΜάμμαλϠΨΠʹ Can we know how many characters it would take to type the expression into wolfram alpha, say?

@Sp3000 𝑓(254560185) = 6

1:48 AM
Oh, that makes sense, since it ends in 1845

So I guess that one was yours?

Time for me to sleep! See you all!

@HelkaHomba Wolfram Alpha wouldn't be able to interpret it

Not promising...

@Dennis Yeah, was testing with some loose change I had lying around

1:49 AM
@LuisMendo night!

@Sp3000 Well, the "loose change" arrived. :)

k, just checking in case I ever wanted to go a bit higher :P

Until now, all my BTC transactions went though. Had far more problems with actual banks.

1:54 AM
@ΛεγίωνΜάμμαλϠΨΠʹ 4038807*6534927 = 26393308912089?
(I'm just trying to go higher until I get a mess of functions again)

Out of curiosity, @ΛεγίωνΜάμμαλϠΨΠʹ, what's N and R?

@Sp3000 𝑓(26393308912089) = 15/2
@DerpfacePython Positive integers and reals
ninja'd

Aw come on, 15/2 doesn't help :/

@Sp3000 Hey, I didn't write the values, only the definition

1:56 AM
6534927*10573734 = 69098579807418?

in the TNB transcript, these are the most common words that follow the word "please", starting with the most common: are use review with a contact check make close combine just not don no roll remove tell read Too forgive stupid
anyone The raise Now impress I do D let vote JoeZ Rusher post Am comment be user give my have leave undelete M
ore Suddenly KevinL sandbox change everyone try say ping Questions p explain ask if edit the minutes stay quali
fy look someone extract Oh P correct Unihedron notify point thanks send take delete submit verify feel Doorknob

To be fair, I highly doubt I'll get this by sheer virtue of not knowing the significance of that Φ function

So how do you find f(n)?

@Sp3000 𝑓(69098579807418) = ₂𝐹₁(1/2238, 1; 2239/2238; 1/3) + 1/12 ₂𝐹₁(2/373, 1; 375/373; 1/3) + 1/21 ₂𝐹₁(7/746, 1; 753/746; 1/3) + 1/326 ₂𝐹₁(163/1119, 1; 1282/1119; 1/3) + 1/746 log(3/2), where ₂𝐹₁ is the hypergeometric function
@DerpfacePython you have to find out ;)
@DerpfacePython it's a (partial) function mapping from positive integers to reals

OK...
So as far as I can see, @Sp3000 is guessing how the function works and you're giving him solutions, @ΛεγίωνΜάμμαλϠΨΠʹ.

2:03 AM
@DerpfacePython yes, you give me 𝑛 and I give you 𝑓(𝑛).

f(1)?

I'm just trying to guess at values which give a result, but given the fact that 1) Legion is simplifying a lot of the results and 2) I don't even know these functions well, I doubt I'll get the intended answer

@DerpfacePython 𝑓(1) is undefined

Um... 100?

@DerpfacePython 𝑓(100) is undefined

2:04 AM
Shooting in the dark here. Uh... 12345?
Wow, this is fun.

@DerpfacePython 𝑓(12345) is undefined

Crap.
21?

@DerpfacePython 𝑓(21) is undefined

22 to 30?
I can ask for a range, right?

2:07 AM
@ConorO'Brien almost poetic
Make close. Combine just.
He, flawr, ungolf, alright!
Trust, share. Enter dumb.`

bah, I forgot to include apostrophes
@HelkaHomba yeah, I thought so too

Can I ask for a range?

Here:
𝑓(22) is undefined
𝑓(23) is undefined
𝑓(24) = 0
𝑓(25) is undefined
𝑓(26) is undefined
𝑓(27) = 0
𝑓(28) is undefined
𝑓(29) is undefined
𝑓(30) = 0
@ConorO'Brien 𝑓(1337) is undefined

420?

@DerpfacePython 𝑓(420) = π²/8

2:10 AM
What's that weird symbol?
Haha, I found one!

@DerpfacePython pi

210?

@DerpfacePython 𝑓(210) is undefined

@DerpfacePython 𝑓(36) = 0

2:11 AM
39?

@DerpfacePython 𝑓(39) is undefined

Yeah, I think I give up :/ Hypergeometric's too hard for me

Hmmm...
1.5?
Or only whole numbers?

@DerpfacePython The domain is positive integers

100000000000000000000000000000?

2:13 AM
@ConorO'Brien 𝑓(100000000000000000000000000000) is undefined

So anything not divisible by 3 is undefined... I think.
5000000000?

@DerpfacePython 𝑓(5000000000) is undefined

12341234?

@DerpfacePython 𝑓(12341234) is undefined

Every multiple of 3 from 40 to 100?

2:15 AM
@DerpfacePython No.

Why no?

Wait one sec

@ΛεγίωνΜάμμαλϠΨΠʹ 1e1000?

@ConorO'Brien 𝑓(10^1000) is undefined

interesting

2:17 AM
So... yes or no on calculating mine?
@ΛεγίωνΜάμμαλϠΨΠʹ?

Here:
𝑓(42) is undefined
𝑓(45) = 0
𝑓(48) = 0
𝑓(51) is undefined
𝑓(54) = 0
𝑓(57) is undefined
𝑓(60) = 0
𝑓(63) = 2
𝑓(66) is undefined
𝑓(69) is undefined
𝑓(72) = 0
𝑓(75) = 0
𝑓(78) is undefined
𝑓(81) = 0
𝑓(84) = π²/6
𝑓(87) is undefined
𝑓(90) = 0
𝑓(93) is undefined
𝑓(96) = 0
𝑓(99) = 2

Thanks!

168?

@ConorO'Brien 𝑓(168) = ζ(3), where ζ is the Riemann zeta function

@ΛεγίωνΜάμμαλϠΨΠʹ 252?

2:25 AM
@ConorO'Brien 𝑓(252) = 1/6(π² - 6 log²(2))

336, 420?

I think I made another breakthrough: for any multiple of 3 from 15, if the only divisors of the number are 2, 3 or 5, the result will be 0.

@ConorO'Brien 𝑓(336) = π⁴/90
@ConorO'Brien 𝑓(420) = π²/8

84 * [1, 2, 3, 4, 5] = [π²/6, ζ(3), 1/6(π² - 6 log²(2)), π⁴/90, π²/8]

108?

2:27 AM
@DerpfacePython 𝑓(108) = 0

117?

@DerpfacePython 𝑓(117) = 2

153?

672 is probs ζ(5) then I guess

@DerpfacePython 𝑓(153) = 2
@Sp3000 𝑓(672) = ζ(5)

2:31 AM
What's 672's prime factorization?

@DerpfacePython 672 = 2⁵⋅3⋅7

2688?

@DerpfacePython 𝑓(2688) = ζ(7)

KK...
10752?
43008?

@DerpfacePython 𝑓(10752) = ζ(9)
@DerpfacePython 𝑓(43008) = ζ(11)

2:36 AM
Ummm... should I make a file for patterns?

@DerpfacePython not my decision

𝑓(5376)?

@GeorgeV.Williams 𝑓(5376) = π⁸/9450

@ΛεγίωνΜάμμαλϠΨΠʹ Is that power on the log meant to be a power or the base?

@DerpfacePython Power, base is subscript

2:42 AM
So it goes through log twice?

@DerpfacePython no, log squared

What is log squared?

@DerpfacePython the square of the log

???
log^2(10) = 4, then?

log²(𝑛) = (log(𝑛))²
@DerpfacePython natural logarithm

2:44 AM
is it some hypergeometric function?

@GeorgeV.Williams what is?

@GeorgeV.Williams can't tell

@GeorgeV.Williams No, I won't tell.

2:46 AM
504?

@DerpfacePython 𝑓(504) = 1/12(21 ζ(3) + 4 log³(2) - π² log(4))

so 𝑓(252) = F(1,1,1;2,2;1/2)

0

In arithmetic, an n-smooth number, where n is a given prime number, is mathematically defined as a positive integer that has no prime factors greater than n. For example, 42 is 7-smooth because all its prime factors are less than or equal to 7, but 44 is not 7-smooth because it also has 11 as a p...

𝑓(504) = 2 Li3(1/2)

@GeorgeV.Williams It should be, given some of the previous responses

2:50 AM
768?

@DerpfacePython 𝑓(768) = 0

𝑓(420) = F(1,1,1;2,3/2;1/2)

1008?

we can do this guys I believe in us

@DerpfacePython 𝑓(1008) = 2 Li₄(1/2), where Li is the polylogarithm function

2:52 AM
What's Li?
Ah

2*3*5*7*11*13 = 30030?

@Sp3000 𝑓(30030) is undefined

2520?

@DerpfacePython 𝑓(2520) = 1/8 Φ(1/2, 3, 1/2), where Φ is the Lerch transcendent

2:56 AM
i see no ಠ_ಠ

@EᴀsᴛᴇʀʟʏIʀᴋ ಠ_ಠ
not cute

but everybody knows angry ducks are the best

conjecture: 𝑓(x) = F(1, 1, 1; 2, g(x); 1/2) where g(x) is some simple function I need to determine

f(252*2^n)=2Lin(1/2)

@HelkaHomba I am heavily biased towards :D I use it all the time