# Bizarre ways of using TeX

These last few days we've suddenly seen huge numbers of instances of things like this: Where it was be appropriate to write $f(x) = a_n x^n + \cdots + a_0$, people instead write f(x) = a$_n$x$^n$ +...+a$_0$. Click on "edit" and look at how that's coded! The subscripts and superscripts are in TeX; the "+" and "=" and "f(x)" and "a" and "..." are not. Or they write $a$ + $b$ = $c$ instead of $a+b=c$, again leaving "+" and "=" outside of TeX. All sorts of variations on this theme.

Here's my suspicion: Suddenly people are getting directed to some software somewhere on the web that purports to do things like this for them without their knowing TeX. And it was designed by illiterates who can't spell. If this site is somehow tacitly condoning this, maybe something should be done about it.

• I have noticed this as well. I don't think it's automated software, as there are too many inconsistencies in the markup. For example, in the same post I might see $a$+$b$ = $c$, and elsewhere $a$ + $b$ = $c$ -- note the inconsistencies in the spacing. – Emily Dec 3 '12 at 18:02
• Yeah, it's kinda strange and quite annoying when people do that. I wonder why they do it. – Asaf Karagila Dec 3 '12 at 18:17
• I don't think it is automated software either. It looks more like the result of not completely understanding how to use TeX. – Eric Naslund Dec 3 '12 at 18:26
• I don't usually proofread people's LaTeX, and try to respect the authors LaTeX formatting preferences, but this is just wrong. Not only is the LaTeX poor, but the rendered image is affected. I would correct the LaTeX and leave a comment pointing the author to our LaTeX tutorial. – robjohn Dec 3 '12 at 18:38
• @Eric: I think that you misplaced the negation there. It looks like the result of completely not understanding how to use TeX. :-) – Asaf Karagila Dec 3 '12 at 19:12
• Can we be certain that (all) the users who are (mis-)using LaTeX this way are really separate individuals? – Old John Dec 3 '12 at 21:27
• I respect authors' esthetic preferences when they're just esthetic preferences, but if they write "mathametician", I correct it, and similarly I change $1,2,3,...,n$ to $1,2,3,\ldots,n$. (And of course I leave their mathematical errors intact when the fact that it's an error is essential to the question.) – Michael Hardy Dec 3 '12 at 22:14
• (I see that $1,2,3,...,n$ doesn't seem perceptibly different from $1,2,3,\ldots,n$ here in the comments, but it's conspicuous in questions and answers, and in ordinary LaTeX documents.) – Michael Hardy Dec 3 '12 at 22:15
• I’ve seen the phenomenon often enough, but I’ve not noticed any recent increase. In some cases it’s pretty clearly a workaround for ignorance, e.g., {$x\in X:P(x)$}. When a poster uses $TeX$ only for those symbols not otherwise available, I also suspect ignorance: this this is thought of simply as a way to produce funny symbols. – Brian M. Scott Dec 4 '12 at 1:23
• I'm not sure there's much to be done about this. In particular, the guideline to typesetting equations linked to in the FAQ already explains how to typeset subscripts and superscripts without using TeX. – Brett Frankel Dec 4 '12 at 14:55

I have to agree that it doesn't seem like the work of any automated software (however badly programmed). It seems likely that such behavior is simply the result of a user relying on $\TeX$ for only the parts of the formatting that they view to be necessary or aesthetically pleasing. In the case of the polynomial, for example, they'd only "need" to use $\TeX$ to get the super- and subscripts, as the normal format has all the letters and symbols. In the case of the $a$ + $b$ = $c$, they may be trying to avoid any confusion between "a" as a variable and as a word, or perhaps they just prefer the smaller + and = to those that result from putting the whole equation in $\TeX$. I'm sure it varies from user to user, but I doubt it's anything to be (overly) concerned about.

• Note that this increases the number of TeX entities to load and display, so it does make a difference at how fast the page is displayed. In addition to the aesthetic aspect. – bitmask Dec 8 '12 at 15:48
• That's a fair point, though the aesthetics are subjective. – Cameron Buie Dec 8 '12 at 15:59
• I to something like that sometimes, when the pure Latex version looks out of place in a block of text. Compare $6\cdot10^{23}$ with 6 · 10²³ and 6 $\cdot$ 10$^{23}$ (the first is pure latex, the second unicode, the third is "mixed" latex.) – jdm Dec 11 '12 at 15:44
• @jdm: And I prefer the first by a significant margin to either of the others. – Brian M. Scott Dec 16 '12 at 22:49

I've done similar things in the past. Didn't use other software - I simply didn't understand TeX properly and was hesitant with the formatting. It is reaaally confusing (but rather rewarding once you get the hang of it).

I suspect that at least some of this is influenced by the way math formatting is handled at Wikipedia, where people are used to just italicizing individual variables in the text using the standard italicization command and where in fact this sometimes produces more pleasing results than a math tag because it keeps the variables at the same font size as the surrounding text. I've seen some posts with things like 'a' recently that tried to mimick this style, and I could imagine that when people notice that this doesn't work they just replace the single quotes by single dollar signs without changing the overall style.

I realise on reading this that I have on occasion been using TeX only where it was necessary to obtain a symbol, and should use it more systematically. I haven't used any automated software. It would I think be helpful for new users if FAQ's said explicitly that mathematical expressions should be formatted entirely in TeX. Currently there is a sentence in FAQ's beginning:

"Our interface supports the use of MathJax by using a LaTeX-like syntax ..."

This could suggest that TeX is just an option to use if you like.

• TeX is just an option to use if you like. Although we do and should encourage all continued users to learn TeX, I'd hate to (accidentally) discourage people from asking questions just because they don't know how to format them. – Brett Frankel Dec 4 '12 at 14:52
• If you're new to TeX, it's fine if you don't know everything about it. But, notice that writing the polynomial (above in the question) is in fact MUCH easier if you write the entire thing inside one set of dollar signs instead of writing several different dollar signs throughout. The point of the dollar signs is that all mathematical expressions should go inside of them. If $x$ is a variable, you would write \$x \$ instead of just plain x because \$x \$ formats it differently to $x$. Notice it is italic. – GeoffDS Dec 6 '12 at 18:24