Unicode Character “𝕏” (U+1D54F)

[mlochbaum]

I'm responsible for this character being supported in Iosevka, JetBrains Mono, 3270, and Cozette, looks like. For arguments I wanted to stick to mathematical convention like f(x) without looking like a regular variable. While the lowercase 𝕩 (subject role) is more common, uppercase makes it a function and is useful in functional programming. More visibility for the character is helpful if it means wider font support, although the real sticking point has been lousy UTF-16 handling on Windows. Like most emoji, these characters need to be represented as a surrogate pair in UTF-16, and terminals in particular often don't handle it.

https://mlochbaum.github.io/BQN/fonts.html

https://mlochbaum.github.io/BQN/help/rightargument.html

[dietrichepp]

This is for math.

In Latex, you get these symbols with \mathbb{}. They are most commonly used to represent to represent number sets, like the set of all integers Z (from the German), set of all natural numbers N, set of complex numbers C, set of all real numbers R, rationals Q (for “quotient”), set of quaternions H (named after Hamilton), or an unknown set F (for “field”). This explains why many of the letters in this series exist in the basic multilingual plane—because R is very commonly used, but A is not. You can find ℝ in the basic multilingual plane at U+211D.

I don’t know why people are interested in the X symbol. It’s just there to complete the alphabet. There are many other ranges like this used for writing mathematical formulas, like the range of bold letters, fraktur, script, etc.

[jhoechtl]

> I don’t know why people are interested in the X symbol.

It's the new symbol for and domain name of the social? network formerly known as twitter.

[orlp]

𝕏 is used as a symbol for a generic metric space. E.g. if your result is generic over ℝ², ℂ³, etc, you can write 𝕏.

[enriquto]

> This is for math.

Heh.

The "tabs vs spaces" debate of mathematical typography is whether these symbols should be used at all in printing, or reserved for actual blackboards. In LaTeX you can have actual boldface letters, so you should write a boldface letter R to represent the real numbers and so on. Using "blackboard bold" in print looks terribly off to some (many?) people.

[formerly_proven]

The "bb" in "mathbb" isn't for "math, baby" (although accurate), but short for "blackboard bold". These letterforms don't originate with blackboards though, using outlines for thick verticals goes back centuries. They're sometimes called open face.

[masukomi]

because elon renamed twitter to "x corp", bought the x.com domain and shoved this character on it.

[snarfy]

They are an accessibility nightmare. I read a comment here recently from a blind person that had to give up on math education entirely due to all of the symbols not being supported by screen readers. It was pretty sad.

[eesmith]

Ooh, I found a use in the wild! https://www.ams.org/books/memo/1023/

  The central theme of this paper is the variational analysis of
  homeomorphisms $h \colon \mathbb X \xrightarrow []{{}_{\!\!\mathrm
  {onto}\!\!}}\mathbb Y$ between two given domains $\mathbb X ,
  \mathbb Y \subset \mathbb R^n$.

[dclowd9901]

Cause “X” is a cool letter. Just ask David X. Cohen.

[jjgreen]

Interesting comment on the Register (by Jedit):

However, it's also exactly identical to Unicode character 1D54F - because that's all it is. And if you examine the full "X" logo in detail, you'll notice that the scratch in the background doesn't reach the X because all the logo creator did was put U+1D54F in a black square and slap it onto the backdrop. It's the epitome of laziness.

https://forums.theregister.com/forum/all/2023/07/24/twitter_...

[spiffytech]

Fun fact: this has happened before!

> Apple's adaptation of the [⌘] symbol — encoded in Unicode at U+2318 — was derived in part from its use in Nordic countries as an indicator of cultural locations and places of interest.

> ...

> She was browsing through a symbol dictionary when she came across the cloverleaf-like symbol

https://en.wikipedia.org/wiki/Command_key

[jonas-w]

You can also access x.com when using the Unicode Character https://xn--971h.com (𝕏.com)

[mkl]

Are you sure? When I type https://xn--971h.com in it doesn't work, but clicking the link in your comment does because HN has made the href x.com. The browser converts 𝕏.com to x.com before going there too. Moreover, X and 𝕏 are treated as equivalent characters in this context, so whois 𝕏.com looks up x.com, and 𝕏.com's punycode encoding is x.com: https://www.whatsmydns.net/idn-punycode-converter?q=%F0%9D%9...

whois xn--971h.com returns the same thing as an unregistered domain.

[N19PEDL2]

Also https://xn--u1a.com is for sale (where х is a Cyrillic letter, see [0]).

Would be funny to buy it and make a redirect to threads.net.

[0] https://en.wikipedia.org/wiki/Kha_(Cyrillic)

[ricardo81]

$ curl -i 'https://xn--971h.com'

curl: (6) Could not resolve host: xn--971h.com

[ranting-moth]

I wonder what Elon paid for x.com?

[danso]

These tweets by @SawyerMerritt seem to have been the "inspiration" for X's logo:

https://twitter.com/SawyerMerritt/status/1683150433806692352

Correction to my previous reply: @ajtourville designed the thicker X logo below for our (now discontinued) @OfficialXPod. The thicker logo was inspired by a font he found online (bottom right). I created the video above using the font logo, adding a glow and little lines in the logo to make it look “imperfect."

https://twitter.com/ajtourville/status/1683151957723160576

Correct. This is the logo I designed and, if @elonmusk wants, he can have it for free.

Maybe I haven't had enough coffee, but the allegedly "designed" thicker X, "inspired by a font [Alex] found online", seems to be exactly the unicode 𝕏, but bold? And this Alex guy is taking the credit for designing it?

[lifthrasiir]

It's actually time for someone to adopt this character [1] at the gold level ($5,000), which is only allowed for the single entity and doesn't expire---so that X.com doesn't have a chance to sponsor the character at the same level.

[1] https://home.unicode.org/adopt-a-character/about-adopt-a-cha...

[bhouston]

Who cares if x.com sponsors it? In fact they should because emojis are so popular on it and Unicode could use the fund. Why should someone try to get this? What is their benefit?

[exegete]

>All sponsors are acknowledged in Sponsors of Adopted Characters and our public Twitter feed and will receive a custom digital badge for their character.

Wait, do they mean their public X feed?

[wigster]

appropriate the new name is the universal symbol for close application

[NoZebra120vClip]

I've started telling people to "just 𝕏 out that window." You can hear the outline typeface in my voice.

[marmitesmuggler]

Strongly reminds me of the X11 logo (one of my favourite designs).

[simplicio]

Yea, kinda feels like X.org would have a decent trademark case if they wanted to pursue it. Both the name and logo are really similar, and it seems like both companies are operating in similar enough categories that its not too hard to imagine there being confusion between the two.

[gjvc]

https://en.wikipedia.org/wiki/X_Window_System yup

[myfonj]

Interestingly, [w3.org Math Double struck] shows example glyph rendering with swapped double stroke stem ("//" + "\" instead of "\\" + "/").

Been looking what the "opf" in the `𝕏` HTML entity name of this kind of character means, and apparently it is "Open Face".

It is referenced at [wikipedia Blackboard bold] that mentions that "𝕏 Occasionally used to denote an arbitrary metric space. "

[w3.org Math Double struck]: https://www.w3.org/Math/characters/double-struck.html [wikipedia Blackboard bold]: https://en.wikipedia.org/wiki/Blackboard_bold

[GaggiX]

I use this X character in my name on Telegram, now everyone will think I'm an Elon stan.

[Zambyte]

Just change your name to the Twitter bird

[hcarvalhoalves]

> X is the future state of unlimited interactivity – centered in audio, video, messaging, payments/banking – creating a global marketplace for ideas, goods, services, and opportunities. Powered by AI, X will connect us all in ways we’re just beginning to imagine.

Audio, Video, Messaging, Payments and AI, all in a single product pitch.

I guess then "X" is an appropriate brand for something that even the owner doesn't know WTF is about.

[floren]

https://zombo.com/

You can do anything at X.com, anything at all!

[tiltowait]

An "everything app" sounds a lot like what I understand WeChat to be. Can't say I want it, but it's not without precedent, apparently.

[pwdisswordfishc]

In other words, X is the new blockchain.

[Dig1t]

Basically Google

[CodeCompost]

Ah so that's how we're supposed to Google for tweets now. "𝕏 something something".

[app4soft]

> Looking forward to #Musk trying to trademark a Unicode symbol, in this case 𝕏 :) Maybe we should start using #x1D54F as the new Hashtag for everything #Twitter and #X #𝕏 :)[0]

[0] https://social.wildeboer.net/@jwildeboer/110768919254064477

[gabugabu]

Beautiful. :):):):)

[petercooper]

Does this affect the potential for trademarking the logo?

[numpad0]

Am I supposed to not notice this mastodon in the room...

[spread_love]

I can see users misreading this as a "close" icon in the "share on..." section of every article

[yaakov34]

Can someone explain what we are talking about here? Something having to do with Musk's son's name?

[Azrael3000]

No it's about the renaming of Twitter.

[0] https://nitter.net/elonmusk

[spiffistan]

Twitter has been rebranded as 'X'. Elon has the domain x.com and I suppose he wants to use it

[superhumanuser]

Twitter is rebranding to X.

[samwillis]

It makes typesetting easer, pretty genius really! /s

We're going to see a trend of companies using Unicode characters for their logo now aren't we?...

[pluc]

I can't wait to x about this. Y'all re-x me when you see it.

[qingcharles]

I tried hitting the X button to re-x you but the browser window closed.

[croes]

Possibly related

https://news.ycombinator.com/item?id=36845492