[HN Gopher] The letter : name and origin? (2017)
___________________________________________________________________
The letter : name and origin? (2017)
Author : IdealeZahlen
Score : 273 points
Date : 2024-11-14 16:28 UTC (1 days ago)
(HTM) web link (mathoverflow.net)
(TXT) w3m dump (mathoverflow.net)
| non- wrote:
| One thing I've always struggled with Math is keeping track of
| symbols I don't know the name of yet.
|
| Googling for "Math squiggle that looks like a cursive P" is not a
| very elegant or convenient way of learning new symbol names.
|
| I wish every proof or equation came with a little table that gave
| the English pronunciation and some context for each symbol used.
|
| It would make it a lot easier to look up tutorials & ask
| questions.
| pflenker wrote:
| I can relate. Ages ago, before Safe Search and search result
| tailored to one's history and preferences, I was trying to
| figure out how to write that big union symbol ([?]) in LaTeX
| and googled for Big Cup LaTeX. I got _very_ different and
| unexpected results.
| vundercind wrote:
| Googling guitar-related stuff is how I learned there's such a
| thing as c-string women's underwear & bathing suit bottoms,
| not just g-strings.
|
| That was, briefly, a real WTF moment.
|
| [edit] oh my god, of course that one didn't come from
| searching guitar topics, that makes no sense given the
| standard tuning. I'm pretty sure I was googling strings in
| the C language when I hit that one, lol. I did probably
| accidentally land on "g string" after searching without
| thinking about what would obviously come up, when looking up
| guitar topics, and must have combined the two incidents in my
| memory.
| Archelaos wrote:
| This reminds me of the time when searching for "c string"
| would probably result in "The C Programming Language" at
| number 1.
| rahkiin wrote:
| That's what I get right now
| dhosek wrote:
| In the early days of the internet, searching for things
| like C++ was really challenging because none of the first
| generation search engines could search for that
| particular string.
| eesmith wrote:
| Back in the mid-1990s I extracted a small part of the GNU
| C++ String library into a small package, which I called
| "GString".
|
| I had no idea about the garment.
| scubbo wrote:
| Haha - my favourite WTF Googling moment was when, as a
| callow youth first setting out in learning Javascript and
| HTML, I Googled "How to get head"
| ssl-3 wrote:
| Eons ago, I was exploring ways to run some outdoor overhead
| wire between my house and the shed.
|
| One method I considered involved using those little self-
| wedging widgets that squeeze down tighter as the thing being
| suspended is pulled harder. (These widgets were once commonly
| used with overhead POTS telephone lines.)
|
| So I asked around and the broad consensus in my area was that
| one of these widgets is called a "horse cock."
|
| And while everyone who knew what I was talking could say it
| with a very straight face, I did not even bother with trying
| to Google "horse cock" before deciding to go in a different
| direction with that project.
| gnopgnip wrote:
| Is that the same as a kellums grip or hubbell device?
| stroop wrote:
| I once noticed a LaTeX installer installing a package called
| he/she (apparently some sort of pronoun swapper). "Latex
| he/she" is not great for work search history.
| moomin wrote:
| Back in the day, a gay colleague of mine forgot the dash in
| the website of the then trading venue Chi-X. He got a very
| threatening page in his browser. I assured him I'd back him
| up in the disciplinary.
|
| What was particularly funny was his look of complete
| incomprehension at why he was getting this message.
| causal wrote:
| Yeah I find that I reason about math in my head with names for
| symbols - the visual shape is not sufficient for the math part
| of my brain to manipulate it as a symbol.
| mindcrime wrote:
| Same. If I see a symbol and can't "say" the symbol, I can't
| (easily) process it. I think over time that gets better and
| eventually it's possible to start to "pattern match" it just
| off the visual representation, but at least for me when
| something is new, I need the "name" of it as something I can
| say to myself or I hit a ParseException. :-(
| narrator wrote:
| At least you can send claude or openai images now of the math
| symbol.
| gengelbro wrote:
| There has been various modernization efforts in the past
| correct? I wonder why nothing has succeeded. Math has always
| been somehow very tied to keeping credit and personal
| achievement close to the "source" it feels. Conjectures always
| coming with names attached, or this symbol named after a
| whimsical stoke of a pen.
| loremm wrote:
| As a first foot-hold I recommend highly
| https://detexify.kirelabs.org/classify.html
|
| (I think I saw there was a newer one, but don't remember how)
|
| You draw the symbol and get the TeX symbol name. I tried this
| one and it does give the right \wp (which in this case is
| confusing and you'd have to look up more about why it's named
| that)
|
| But for classic ones, for instance the "upside down A" ->
| "forall" is very helpful and shakes newcomers to math syntax
| nine_k wrote:
| Feynman said that his students struggled with a reverse
| problem: how to know that "harnew", an important part in QM
| equations that the lecturer talks about, actually stands for
| _hn_.
| 12thhandyman wrote:
| Always thought it was kind of cool how Feynman writes
| about, when learning calculus and maths as a younger
| student, would create and use his own symbols for things
| and how it worked well for him. But kind of realized if he
| was going to enter the scientific community would need to
| conform to the standardized notation/symbols for equations
| etc.
| crdrost wrote:
| We solved that though, it's now pronounced "(h)aitch-bar-o-
| mega."
| nine_k wrote:
| Everything is easier with a piece of pi!
| teddyh wrote:
| See also: <https://shapecatcher.com/>
| non- wrote:
| This is great, thank you! Would be even better if it had a
| little "click here to hear it said out loud" button.
| esafak wrote:
| Detexify appears to be a kNN classifier. https://gist.github.
| com/kirel/149896/3a13825f826ec91e04d4adb...
| dtgriscom wrote:
| Good stuff: worked the first time I tried to draw a .
| meowster wrote:
| Very cool, but I tried a plus ("+"), and it didn't show up in
| the list, even when I clicked "show more" several times.
| madcaptenor wrote:
| I have seen math textbooks that have a "table of symbols" or
| similar, by the table of contents or the index. It's really
| helpful. Also nice to have - a "map of the book" (I don't know
| a better name for this) which indicates graphically which
| sections of the book depend on which other sections.
| "Dependency graph", maybe?
| QuercusMax wrote:
| I wish music books would do this too - I've been self-
| teaching myself a little classical guitar, and some of the
| scores I'm reading have various symbols that have taken me
| quite a while to figure out. I eventually determined that a
| bold III means to play in third position in some books, but
| these things aren't consistent between publishers.
| dhosek wrote:
| Classical music is relatively standardized. Roman numerals
| to indicate position are standard practice for all string
| instruments (I remember learning this as a beginning bass
| player as a kid). You will sometimes see Roman numerals
| used as a means of identifying chords relative to the tonic
| of the current key, but that's uncommon and the notation is
| a bit different than the position notation in how it's
| placed on the staff (if it even appears on the staff and
| not in a harmonic analysis).1 I've not seen the upper- and
| lower-case distinction in roman numeral notation I learned
| somewhere which uses cases to distinguish between major and
| minor in any classical music harmonization texts, but I may
| have just paid insufficient attention.
|
| [?]
|
| 1. I have a vague notion that it might show up in figured
| bass once in a great while, but I could be wrong.
| madcaptenor wrote:
| This all seems right to me. As for your figured bass
| comment, you could have something like iii^6_4 for an e
| minor chord with the B in the bass, when the key is C
| major. But if you were writing it next to the staff you
| wouldn't need to write the iii - it's implied by the bass
| note and the figures, and classically figured bass writes
| the minimum it has to, for example just 6 instead of 63
| for a first-inversion triad.
| QuercusMax wrote:
| I've played lots of piano and wind music and took lessons
| for that stuff in school, but I've been self-teaching
| guitar / ukulele / bass / mandolin in a smattering of
| different styles, which is probably part of my issue. I
| go through cycles where I'll focus on one instrument and
| style for a few weeks - in the last year I've dabbled in
| bluegrass banjolele, Irish fiddle tunes on mandolin, jazz
| on bass and keys, rock electric ukulele, funk piano, rock
| organ... And that's not even an exhaustive list.
| column wrote:
| But nowadays you can simply ask a vision model
| jacobr1 wrote:
| yep, or even just a text model
|
| ChatGPT 01-preview gave me:
|
| User: what is the Math squiggle that looks like a cursive p?
|
| Assistant: The mathematical symbol you're referring to is
| likely the Weierstrass \wp function symbol, which resembles a
| cursive or script "p":
| graycat wrote:
| Uh, symbols and math??? Uh, as I read mathematical physics, I
| get the impression that certain symbols in certain equations
| are accepted throughout physics as already defined. But in
| math, we have, e.g.,
|
| "For the set of real numbers R, some positive integer n, and
| R^n, with both R and R^n with the usual topologies and sigma
| algebras, we have function f: R^n --> R, Lebesgue measurable
| and >= 0."
|
| That is, in writing in math, a popular but implicit standard
| is, each symbol used, even if as common as R and n, is defined
| before being used.
|
| Sooooo, right there in the math writing, the symbols are
| defined. Or, right, an author might assume that the reader
| knows what "the usual topology" or "Lebesgue measurable" are
| but does not assume the reader knows what the symbols mean.
| I.e., the issue is not something about helping readers with
| their knowledge of math but, instead, just being clear about
| the symbols. Or, can assume the reader DOES know about the real
| numbers but does NOT assume that R is the set of real numbers
| -- and correctly so because R might be the set of rational
| numbers, some group (from abstract algebra), nearly anything.
|
| Again for physics, E = mc^2 and J = ns^2 are not the same, not
| within the standards, maybe even if say J is energy in Joules,
| n is mass, and s is the speed of light!!!
| jltsiren wrote:
| The standard is based on the expectation that you should be
| able take a definition or a theorem out of its context and it
| should still make sense. The same symbols are often used for
| different things in different contexts, while concepts (even
| advanced ones) tend to remain unambiguous.
|
| R is unambiguous if it's in blackboard bold, but otherwise it
| can mean almost anything. n is likely interpreted as a non-
| negative integer if left undefined, but you usually need to
| establish explicitly if it can be 0.
| Symbiote wrote:
| The "unicode" program (in Ubuntu's package repository) gives
| the Unicode entry for any character: $ unicode
| U+2118 SCRIPT CAPITAL P UTF-8: e2 84 98 UTF-16BE: 2118
| Decimal: ℘ Octal: \020430 Category: Sm
| (Symbol, Math); East Asian width: N (neutral) Unicode
| block: 2100..214F; Letterlike Symbols Bidi: ON (Other
| Neutrals) Age: Assigned as of Unicode 1.1.0 (June, 1993)
|
| Or you can ask Wikipedia:
| https://en.wikipedia.org/wiki/%e2%84%98 (manually URL-escaped
| for HN)
| anyfoo wrote:
| That assumes you are in a position of being able to paste the
| character (and as unicode), which is not always the case.
| zamadatix wrote:
| If you already have a copyable version of the character it
| also works in the original Google search. Or any other place
| you can put it. The problem is when you don't have the
| literal character as text (say, an image, video, or non-
| digital source) and need to reproduce it to do that lookup in
| the first place.
| layer8 wrote:
| > Googling for "Math squiggle that looks like a cursive P" is
| not a very elegant or convenient way of learning new symbol
| names.
|
| Asking ChatGPT (or the like) is a good solution nowadays
| though: "The mathematical symbol that resembles a cursive "p"
| is likely the Weierstrass p, denoted as . [...]"
| flatline wrote:
| I asked once and it just gave me "p". I said "no more fancy
| like" and it produced the correct result. This is the real
| power of the model for narrowing search, you can interrogate
| the results.
| bregma wrote:
| I heard as many names for the "\partial" symbol as I had math
| professors in university. At least they all wrote them the
| same.
| JohnKemeny wrote:
| "del" is the only way
| gjm11 wrote:
| Except that "del" is also (and I think more commonly) the
| name for the upside-down Delta used in vector calculus for
| div, grad and curl.
|
| (I usually say "partial dx by dt" or whatever, which seems
| OK to me.)
| manvillej wrote:
| I have this little book that I cannot find right now that is
| pretty explicitly that. just a little math symbol dictionary.
| its small enough to fit in a pocket and was invaluable all
| through college.
| mindcrime wrote:
| As somebody who spends a fair amount of time studying math
| heavy material that uses math that I never studied formally,
| this stuff is the bane of my existence. It's one thing to see a
| random Greek letter, where at least I very likely know what the
| character "is" (eg, "rho" or "psi" or whatever) and can at
| least pronounce it to myself and make a mental note "go back
| and see what rho stands for in this equation". But exactly like
| you say "squiggle that looks like a cursive P" doesn't easily
| admit a mental placeholder, AND it's hard to look up later to
| find out exactly what it is. I've really wanted to tear my last
| hair out over this a few times. And I am pretty sure one recent
| such occasion involved this exact character, so this really
| hits home!
|
| And never mind that cognitive load that comes from managing the
| use of symbols that are the "same symbol" modulo something the
| typeface. Trying to read something like
|
| "Little b equals Fraktur Bold Capital B divided by (q times
| Cursive Capital B) all over Gothic Italic B", blah, blah...
| then throw in the "weird little squiggle that looks kinda like
| a 'p' but not quite". It's insane.
| mmooss wrote:
| The Unicode charts for the mathematical symbol ranges can
| serve as a visual index: [0]
|
| They open as PDFs and have grids of all the symbols, along
| with useful metadata such as related and similar symbols,
| common substitutes, alternate names, etc. You won't find
| everything in those ranges - some things are elsewhere in
| Unicode, in their native language or already located
| elsewhere in an earlier version - but it's a great resource.
| Even for symbols that are merely letters in some language's
| alphabet, Unicode sometimes provides a unique codepoint
| (character) for their use in mathematics.
|
| [0] https://www.unicode.org/charts/
|
| That provides each table as a separate PDF downlod:
| mathematics covers ~20 PDFs, each named for its contents. It
| may be faster to download the entire Unicode standard as one
| PDF (~140 MB):
|
| https://www.unicode.org/Public/16.0.0/charts/
| wbl wrote:
| Once there was a lecture at Yale, and Serge Lang, a frequent
| loud critic of bad notation was in the audience. There was a
| function Xi, and soon it was joined by its complex
| conjugation. Then they were divided. Serge Lang walked out.
| gjm11 wrote:
| That's delightful, but I fear many in the audience here may
| not quite see why. So, at the risk of explaining too much:
|
| The Greek letter xi is one of those where the capital and
| lowercase versions are very different. Lowercase is a bit
| like a curly E. Uppercase is (at least if you're writing it
| in a hurry) basically three horizontal lines on top of each
| other.
|
| The operation called complex conjugation can be notated in
| two ways, but the more common one among mathematicians is
| to put a horizontal bar above the thing being conjugated.
|
| So the conjugate of Xi is ... four parallel horizontal
| lines.
|
| And now we divide Xi (three horizontal lines) by Xi-bar
| (four horizontal lines), getting: eight horizontal lines.
| neochief wrote:
| You were explaining this for someone like me. Thanks for
| that!
| hanche wrote:
| In fact, here is the dreaded letter: Ks And its lowercase
| version: x
| sumanthvepa wrote:
| Thank you. That actually was helpful. In print it might
| have been legible, but on a blackboard that would been
| difficult to read.
| bradrn wrote:
| A lovely story, but sadly this recollection from Paul Vojta
| disagrees on his reaction:
| https://www.ams.org/notices/200605/fea-lang.pdf (see p547)
| jacobolus wrote:
| It was a joke. The lecturer (Barry Mazur, at Harvard) had
| made a T-shirt with Lang's catchphrase "This notation
| sucks" and was trying to get Lang to say it with the most
| over-the-top example of bad notation he could come up with
| so he could bring the shirt out, but Lang didn't say
| anything so the whole thing was a bust.
| wwalexander wrote:
| I also find it frustrating, but I've come to appreciate that
| it's a way to at least partially sidestep the hard problem of
| naming things. There are still idioms and choices to make,
| but using abstract symbols makes it easier to play with the
| abstract concepts being presented.
|
| My most-used programming language is Go, but I've been
| writing mainly Swift for the past year or so. While there's a
| lot I like about Swift, its verbosity leads me to waste an
| inordinate amount of time pondering what the correct verbiage
| ought to be, and I often miss Go's more terse, often single-
| character naming convention.
| lmm wrote:
| > My most-used programming language is Go, but I've been
| writing mainly Swift for the past year or so. While there's
| a lot I like about Swift, its verbosity leads me to waste
| an inordinate amount of time pondering what the correct
| verbiage ought to be, and I often miss Go's more terse,
| often single-character naming convention.
|
| Huh. I was expecting that comparison to go the other way
| given Go's notorious verbosity in terms of error handling,
| generics etc.. Maybe people compensate for verbosity in one
| area by being more concise in others (though that doesn't
| explain e.g. APL).
| wwalexander wrote:
| I would say that Go is extremely explicit, but I wouldn't
| say it's verbose.
|
| Or, I suppose you could say that Go is semantically
| verbose (explicit error handling, no/low use of generics,
| no operator overloading), but syntactically concise
| (short variable names). Swift is the opposite, being
| semantically concise (extremely heavy use of generics,
| default arguments) but syntactically verbose (labeled
| arguments, English-like clauses, result builders).
| eurekin wrote:
| I distinctly remember the first time a lecturer used the
| "dx/dt" "symbol" in normal algebraic operations (that is,
| multiply both equation sides by dt and so on). I was so
| shocked it's actually not a elaborate differentation symbol,
| but something with actual division. Next time it was similar
| with integration, where the dx was substituted by some other
| function of du.
|
| I swear I treated those as some grammar token, which doesn't
| hold any real meaning. I've been using those as such for
| years before.
| impendia wrote:
| Technically, dx/dt is _not_ a fraction, but, but, ...
|
| https://mathoverflow.net/questions/73492/how-misleading-
| is-i...
| xg15 wrote:
| This. Related to that, I'll also never get used to
| mathematicians' habit to assign semantic meaning to the _font_
| that a letter is drawn in. Thanks to that, we now have R, Bold
| R, Weirdly Double-Lined R, Fake-Handwritten R, Fraktur R and
| probably another few more.
|
| All of those you're of course expected to properly distinguish
| in handwriting.
|
| I'm sure most of them have some sort of canonical name, but I'm
| usually tempted to read them with different intonations.
|
| (Oh and of course each of those needs a separate Unicode
| character to preserve the "semantics". Which I imagine is
| thrilling edgy teenagers in YouTube comments and hackers
| looking for the next homograph attack)
| jacobolus wrote:
| "Bold R" and "Double-Lined R" (i.e. blackboard bold) are
| semantically equivalent. As your next paragraph hints toward,
| the purpose of the second one is to be distinguishable from
| the regular italic or Roman R in handwriting (or on a
| typewriter).
|
| "Fake-Handwritten R" is an extra fancy calligraphic version
| which is not hard to distinguish. The Fraktur R is a pain to
| write, but you can write an upright "Re" as an alternative.
|
| The basic issue is that using single symbols for variables is
| very convenient (both more concise and less ambiguous than
| writing out full or abbreviated words when writing
| complicated mathematical expressions), but there are
| infinitely many possible variables and only a small set of
| symbols.
| dhosek wrote:
| Yes and no. Generally blackboard bold has come to denote
| particular number sets while bold usually refers to vectors
| or matrices. There are a handful of traditionalists1 who
| will use *R* for the reals or *Z* or even _Z_ for the
| integers, but the trend toward blackboard bold is, I think,
| definitely where things are going.
|
| [?]
|
| 1. I would put Donald Knuth in that category, given his
| choice to not include blackboard bold in his original
| inventory of characters for Computer Modern, but that might
| just as much have been a choice based more on limitations
| of the computing systems he was working with at the time
| (or his needs for typesetting _The Art of Computer
| Programming_ which were the primary driver of TeX).
| jacobolus wrote:
| Whether you write bold R, Z, Q, C or blackboard bold for
| these number sets nobody at all is going to be confused -
| they appear in both ways all over the place in books and
| research papers - and if you mix ordinary bold R, Z, Q, C
| next to the blackboard bold versions of the same upper-
| case letters in a single document then your friends
| should tell you to knock it off.
|
| As for "where things are going" - this has been changing
| extremely gradually over the past 60 years. If the trend
| accelerates maybe you'll stop seeing both variants in
| wide use in about another century.
| dhosek wrote:
| > in about another century.
|
| That sounds about right. Maybe even 50 years, but it is a
| rather slow process.
| seanhunter wrote:
| Springer for example uses capital bold Z, I, Q, R, C, not
| blackboard versions in most of their books whereas
| Cambridge University press seems to go for Blackboard
| bold.
|
| On the other hand "Wolfram" (tspfka "Mathematica") seems
| to not only use the uppercase blackboard bold for Reals,
| Integers etc but also use lowercase blackboard bold for
| i, e, c_x (arbitrary constants) etc. Which is just
| annoying.
| anigbrowl wrote:
| _only a small set of symbols_
|
| I grind hundreds of flashcards every night to learn
| Japanese and I can assure you that one thing we are not
| short of is symbols. Chinese characters use ~218 basic
| symbols which can be stacked and combined to form tens of
| thousands of characters. There are 350 symbols _just for
| counting different kinds of things_.
|
| https://www.tofugu.com/japanese/japanese-counters-list/
| BalinKing wrote:
| Tangentially related: Category theorists sometimes denote
| the Yoneda lemma by yo.
| thaumasiotes wrote:
| > I'll also never get used to mathematicians' habit to assign
| semantic meaning to the _font_ that a letter is drawn in
|
| You never learned to use capital and lowercase letters
| differently? Why did you capitalize the 'i' in "I'll"?
| card_zero wrote:
| This is what you get if you insist on using single letters
| for every variable. Why do that? Well, because otherwise a
| variable name might be confused with a bunch of variables
| multiplied together, because we don't use multiplication
| signs. Why not? Well you see, the signs might be confused
| with the variable x.
| jansan wrote:
| We had a guy in class at high school who was a math prodigy,but
| hated the greek alphabet. He always said things like "If we
| multiply the symbol that I don't know with the square root of
| the other symbol that I don't know..." He was proof for me that
| you can be really good at (high school) math without knowing
| all the symbols' names.
| paulddraper wrote:
| Well rarely do you see a symbol with zero context.
|
| You're reading something. "Oh this has something to do with
| Weierstrass...."
| raldi wrote:
| If you can get it on your clipboard, you can usually paste it
| into Google or append to `https://en.wikipedia.org/wiki/` and
| get the answer.
| anigbrowl wrote:
| This is something I dislike intensely about pro mathematicians.
| If you need that many symbols, document them properly and work
| to ensure they're on the flyleaf of _every_ mathematics
| textbook. You can easily picture a math paper that reads like
| [ ], but [ ]; however [ ] and [ ], so [ ]....
|
| with the spaces being filled in by signatures of famous
| mathematicians.
| omega3 wrote:
| Claude worked it out from that description.
| max_ wrote:
| I keep on saying that math is not hard.
|
| It's just so disorganised that it's hard for people who are not
| passionate about it to study.
| tombert wrote:
| It's what drives me nuts about people making custom operators
| on Haskell.
|
| A word is easy to search, but something like "~~>>=>" doesn't
| really give anything and it's not nearly as cute as the writers
| of the libraries seem to think it is.
|
| I know about Hoogle but that's not a solution, as that only
| searches documentation, not stuff like Stackoverflow.
| tome wrote:
| I randomly chose *> to search for on Google. It does pretty
| well, and yes, the top result is StackOverflow.
|
| https://www.google.com/search?q=*%3E&iflsig=AL9hbdgAAAAAZzeB.
| ..*
| tombert wrote:
| Huh, fair enough, I feel like that must be recent because I
| was having trouble with that before, but maybe it was never
| as bad as I thought it was.
|
| I'll admit I was wrong!
| 5040 wrote:
| I was asking ChatGPT about a "squiggled s" yesterday. It
| thought I meant ss, but the character I was actually interested
| in was SS. Context was obscure keyboard layouts.
| noman-land wrote:
| Local LLMs have helped me a lot in this regard. Even something
| as simple as "how do I say this formula out loud in words?"
| helps tremendously.
| nox101 wrote:
| I was going to say "Use Google Lens" but then I tried it on the
| character above and it utterly failed :D
|
| In any case, there are lots of camera based apps for either OCR
| (So you could maybe search for the character) or image search
| or LLM search (I didn't try ChatGPT).
|
| I did try zooming 300% and grabbing that character as well as
| the whole title as an image at 100% zoom with Google Lens. It
| still failed in both cases.
| zusammen wrote:
| I think one's getting a lot of upvotes from people who meant to
| click on the link.
| tim-kt wrote:
| Yes, this happened to me
| dang wrote:
| You can always click 'unvote' in the detail line.
| wduquette wrote:
| I left college with a math degree and a profound antipathy for
| weird cursive symbols. The one that nearly killed me was the
| Greek "xi". I couldn't pronounce it, and I couldn't write it with
| any fluency, and in some of the classes I took it was
| _everywhere_.
| layer8 wrote:
| Despite only having a CS degree, I was always especially fond
| of x due to its distinctiveness (and also didn't have trouble
| writing or pronouncing it), moreso than letters like n or i,
| which are too close to _v_ or _i_ / _j_ visually for my taste.
| anyfoo wrote:
| I think iota is fine because it's missing the dot that an i
| has, but nu is terrible, yeah. In fact, in some fonts nu is
| _exactly_ v: https://en.wikipedia.org/wiki/Nu_(letter)
|
| But then a lot of capital greek letters at least are
| identical to latin letters in those fonts, so I guess you
| have to choose carefully anyway... and pick the proper
| font/handwriting if you absolutely _have_ to use nu.
| (Hopefully you don 't.)
| anyfoo wrote:
| I encounter x (xi), and also z (zeta) a lot. Honestly, when I
| write them out by hand, I just make a "wild squiggly line" for
| x and a "simplified squiggly line" for z.
|
| If I write it out by hand, it's most likely just for my eyes
| anyway, and I'd type it out on a computer if I'd want others to
| have a look at it. But even if I gave someone else my
| handwritten note, I think from context it would be pretty clear
| what the "squiggly lines" are supposed to be.
| Symbiote wrote:
| z is essentially a cursive z. x is near enough to a backwards
| 3.
| andrewshadura wrote:
| x is literally three horizontal bars underneath each other,
| in cursive.
| jacobolus wrote:
| Indeed. Try to write Ks sloppily using connected strokes
| and you'll end up with something vaguely like x.
| thaumasiotes wrote:
| > x is literally three horizontal bars underneath each
| other, in cursive.
|
| And? So is 3.
| hanche wrote:
| The unstated point is to explain the connection between
| lowercase x and uppercase Ks.
| wduquette wrote:
| When I was an undergraduate typing it out on a computer
| wasn't an option, not with the hardware available at my
| school. It was handwritten, or nothing.
| cvoss wrote:
| I actually find xi easy to write, whereas zeta is really hard
| for me. I think the middle loop of the xi provides an anchor
| for what I'm aiming for, but zeta ends up as a nondescript
| squiggle. Sometimes I can't even properly picture what zeta
| looks like in my head. Is it like a 2, a 5, an S, or a Z? Or a
| cursive C or an italic G? It's all undifferentiated in my head.
|
| I do still remember the day our math professor taught us both
| symbols. He did it very purposefully, like he knew it was all
| riding on him, and we'd all be lost if he didn't pass the
| arcane knowledge down.
| evan_piermont wrote:
| There is a famous anecdote [0] about Barry Mazur coming up with
| the worst notation possible at a seminar talk in order to annoy
| Serge Lang. Mazur defined Ks to be a complex number and
| considered the quotient of the conjugate of Ks and Ks. (Click
| link to view 8 lines on top of each other)
|
| [0] https://mathoverflow.net/questions/18593/what-are-the-
| worst-...
| shoo wrote:
| Paul Vojta p546 http://www.ams.org/notices/200605/fea-
| lang.pdf
| science4sail wrote:
| I must confess that I have an irrational fondness for the use of
| weird symbols in math and technical documents, whether it's for a
| homework assignment in school or a white-paper for work.
|
| My unit tests are literally full of hieroglyphics. My favorite
| design doc to this day is one where I sprinkled Sumerian
| cuneiform throughout the text, e.g. and (Gilgamesh and Enkidu)
| instead of Alice and Bob.
| a57721 wrote:
| I'm not sure if this is a good idea, especially in code; apart
| from adding unnecessary confusion for the reader, this will
| also confuse some monospaced fonts.
| wil421 wrote:
| Glad I'm not GPs coworker. Time to refactor Gilgamesh.
| gweinberg wrote:
| I just see boxes, not the cuneiform.
| starfezzy wrote:
| `pacman -S noto-fonts noto-fonts-cjk noto-fonts-emoji`
| Aloisius wrote:
| I've seen emoji used for Alice/Bob/Carol/etc which is a bit
| more widely supported than old dead scripts.
|
| I await the inevitable mathematical constant unicorn emoji.
| winwang wrote:
| I was following you up until that first comma.
| BalinKing wrote:
| Reminds me of Lamport's original paper on Paxos, in which he
| eschewed Alice, Bob, et al. in favor of [?]Vikstra, Gouda,
| PnuelVi, and a whole host more.
| ugurs wrote:
| Strangely, the most comfortable I've felt with symbols was when
| learning quantum computing. At the time, there was no established
| standard (perhaps it has a standard now), but the symbols were
| used more intuitively than any other math class I've taken.
| Symbiote wrote:
| In the same Unicode block is "2129 TURNED GREEK SMALL LETTER
| IOTA" with explanation "unique element fulfilling a description
| (logic)".
|
| That seems a ridiculous choice for a symbol -- turning one of the
| most symmetrical letters upside down!
|
| Background:
| https://philosophy.stackexchange.com/questions/51563/what-is...
| Archelaos wrote:
| It could be motivated by the fact that Russell and Whitehead
| needed a symbol for printing that the printer had in his type
| case but could not be confused with anything else. Taking a
| iota and simply turning it upside down would then be a rather
| ingenious idea. But that is just my speculation ...
| eesmith wrote:
| https://math.stackexchange.com/questions/1885938/whats-
| meani... says 'in the article Frege, Peano and Russell on
| Descriptions: a Comparison, Francisco A. Rodriguez-Consuegra
| tracks down the source to Peano's Studii di logica matematica
| (1897) as where the operator first appears'
|
| That page in 'Studii di logica matematica' appears to be
| https://archive.org/details/peano-studii-di-logica-
| matematic... .
|
| It also uses an upside-down C and upside-down E.
| Archelaos wrote:
| And the Lambda looks like an upside-down V. The bases of
| all these upside-down letters do not match the baseline of
| the text. Obviously there were no special upside-down
| moveable types available of freshly cast for this book.
| Peano had to creatively repurpose what types were
| available.
| masfuerte wrote:
| There are loads of examples of this, e.g. [?] and [?], but
| iota is a really poor choice.
| schoen wrote:
| In the font on my phone it looks confusingly reminiscent of
| Hebrew vav.
| hinkley wrote:
| My first thought on seeing this title was, "this should totally
| be the name of a programming language descended from Go"
| xg15 wrote:
| "The letter formerly known as p"
| cubefox wrote:
| One thing I like about programming languages is that they usually
| constrain themselves to strings of ASCII characters, instead of
| using lots of more or less inscrutable symbols like mathematics
| does. For example, where a mathematician writes "S", a programmer
| simply writes "sum".
| mmooss wrote:
| You are holding up code as an example of clarity and
| scrutability, and because it is mostly restricted to ASCII? Hex
| code is even simpler - only 16 characters.
|
| > where a mathematician writes "S", a programmer simply writes
| "sum".
|
| Communities develop shorthand and terms of art for things they
| write a lot. Mathematicians need to write lots of sums;
| programmers have their own shorthand and terminology.
| cubefox wrote:
| Hex code doesn't allow you to write words. And "sum" is
| simply better than "S". There is no way to know in advance
| what the latter means, while for the former understanding of
| verbal English is enough. Mathematicians basically use an
| iconographic writing system like Chinese.
| anigbrowl wrote:
| I wish they did, because then it would be more consistent
| and properly documented.
| mmooss wrote:
| We can think of many other strings used by programmers that
| are not common English, and many strings used by
| mathematicians that are.
|
| I think the difference is that you are a programmer and not
| a mathematician (I'm guessing) and are saying, effectively,
| that what you are subjectively familiar with is objectively
| more universally understood.
| card_zero wrote:
| This argument works both ways, apart from it's the
| mathematicians who are wrong.
| mmooss wrote:
| Yes it does work both ways. Any mathematician or
| programmer who uses it is, afaict, just imagining their
| subjective perspective is some objective universal truth.
| cubefox wrote:
| > We can think of many other strings used by programmers
| that are not common English, and many strings used by
| mathematicians that are.
|
| Are you saying special symbols aren't more common in
| mathematics than in programming? I simply disagree.
| Mathematicians hardly use strings at all, e.g. for
| function names or variables, while they are very common
| in programming. Mathematicians mostly use single letters
| in Roman or Greek alphabet, and sometimes with various
| strange styles like fraktur, double strokes etc.
| int_19h wrote:
| Programmers also write something like *[3]int instead of
| "pointer to array of 3 integers" in most PLs.
|
| (Modula-2 tried the latter, but it didn't stick.)
| zahlman wrote:
| >>> import unicodedata >>> unicodedata.name('')
| 'SCRIPT CAPITAL P' >>> ord('') 8472
|
| https://en.wikipedia.org/wiki/Letterlike_Symbols
|
| Good enough for me.
|
| Notably, this is distinct from ("MATHEMATICAL SCRIPT CAPITAL P").
|
| > Books were printed in Fraktur, where the p looks quite normal,
| i.e., quite different from a handwritten Sutterlin p which could
| explain, why it hasn't been replaced in the publication of
| Amandus Schwarz.
|
| Indeed. ("MATHEMATICAL FRAKTUR CAPITAL P") is also separate (but
| also, Unicode considers these mathematical symbols to exist
| separately from "text written in Fraktur script". So you get
| separate characters allocated for these symbols, but they're not
| intended to be suitable for printing in Fraktur - which is
| supposedly a presentation (i.e. typeface selection) issue.
|
| Personally I'm not convinced that mathematical symbols derived
| from Latin or Greek (or other) scripts really have any claim to
| being separate "characters". Surely that's what variation
| selectors are for?
| robinhouston wrote:
| I think the answer by teika kazura on the linked page explains
| pretty thoroughly why this is not "good enough". Most
| importantly:
|
| > In Unicode the letter is given the codepoint U+2118 in the
| block "letterlike symbols", named "script capital p". But in
| fact it's lowercase.
|
| Unicode technical note https://www.unicode.org/notes/tn27/
| clarifies:
|
| > Should have been called calligraphic small p or Weierstrass
| elliptic function symbol, which is what it is used for. It is
| not a capital "P" at all. A formal name alias correcting this
| to WEIERSTRASS ELLIPTIC FUNCTION has been defined.
| ahartmetz wrote:
| There is an old convention in physics - from the time when
| Germany was world-leading in physics - to write vector-valued
| variables in Fraktur. Using cursive (old German cursive is weird)
| seems related, though AFAIU the "vectorness" of the function is
| just the two components of a complex number.
| hanche wrote:
| And algebraists often use lowercase fractur for ideals.
| vanderZwan wrote:
| If you click the link to the wikipedia page on Sutterlin[0] that
| is mentioned in one of the answers, there's a link to _another_
| wiki page about the Antiqua-Fraktur dispute[1]. Apparently 19th
| and early 20th century Germany had a whole nationalistic debate
| about which handwriting script should be used, with the nazis
| ending it by preferring (somewhat surprisingly, to me) the
| _international_ choice of the Latin alphabet.
|
| Combine that with Gottingen being the capital of the maths world
| at the time [2], and I wouldn't be surprised if that dispute had
| some (now mostly forgotten) influences on funny maths squiggles
| in general.
|
| Tangentially, the original question feels somewhat asked in bad
| faith imo, calling many names "bad" with unearned authority, and
| implicitly seeking popular votes to support their position. Also
| sentences like:
|
| > _BTW Abramowitz & Stegun uses P. Wow. See p 629._
|
| It's great if you're passionate about maths, but clutching pearls
| over the use of "P" instead of "" is a bit much (reminds me of
| the "p vs t" debate and how upset that seems to make some
| mathematicians. Meanwhile Euler, who came up with using "p" as a
| circle constant, wasn't consistent about what value he gave it at
| all[3] - he'd just pick whatever circumference-to-radius ratio
| worked best for his proof at hand).
|
| It's pretty clear that "" essentially originated as a Fraktur-
| based glyph that most Germans of the time would intuitively read
| as the equivalent of "P" in Antiqua. The letter "P" is pronounced
| "Pe" in German. No mathematician would have been confused by
| Abramowitz & Stegun's notation, just like writing "R" instead of
| "R" won't confuse anyone either.
|
| Also Milton Abramowitz was a Jewish man. He might have felt a
| certain way about using letters associated with German
| nationalism, but that's just me speculating.
|
| [0] https://en.wikipedia.org/wiki/S%C3%BCtterlin
|
| [1]
| https://en.wikipedia.org/wiki/Antiqua%E2%80%93Fraktur_disput...
|
| [2] https://theconversation.com/how-one-german-city-developed-
| an...
|
| [3] https://www.youtube.com/watch?v=bcPTiiiYDs8
| cryptonector wrote:
| To me \wp looks like a plain cursive p. Had I never seen it
| referred to as a special character I would have thought it was a
| lower-case p. There are many "styles" of cursive writing. But
| it's nice to have specific styles of these letters for use in
| mathematics.
| purplejacket wrote:
| So this letter is distinct from another unicode symbol (that I
| can't copy-paste here?), which we often use for "power set" in
| math; it's given by U+1D4AB.
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