# Mathjax syntaxes that don't look very good?

These MathJax syntaxes look fine to me:

\require{cancel}\cancel{\Longleftrightarrow} $$\require{cancel}\cancel{\Longleftrightarrow}$$

\nLeftrightarrow $$\nLeftrightarrow$$

\nRightarrow $$\nRightarrow$$

\nLeftarrow $$\nLeftarrow$$

\require{cancel}\cancel{\Longrightarrow} $$\require{cancel}\cancel{\Longrightarrow}$$

\require{cancel}\cancel{\Longleftarrow} $$\require{cancel}\cancel{\Longleftarrow}$$

Now, what can we say about these Mathjax syntaxes?

\require{cancel}\cancel{\Leftrightarrow} $$\require{cancel}\cancel{\Leftrightarrow}$$

\not \Longleftrightarrow $$\not \Longleftrightarrow$$

\not \Longleftarrow $$\not \Longleftarrow$$

\not \Longrightarrow $$\not \Longrightarrow$$

Seems like it doesn't look very good to me ...(essentially the first two)

• Can these syntaxes be considered good?

• Can we do the long version of this syntaxis?

\nLeftrightarrow $$\nLeftrightarrow$$

Because,as it seems \nLongleftrightarrow syntax

$$\nLongleftrightarrow$$ doesn't work.

• It might be a good idea to also be kind to comment after down-vote. Mar 27 '21 at 16:25
• You question will only mean anything if you use, e.g. if you include the formatting before revealing the output. Everything wrt what you like could have been preceded by once writing, at the start of the list $\require{cancel}$ which doesn't appear: (blank) $\require{cancel}$. After doing that. everything in that list could have been written with $\cancel{foo}$ to get $\cancel{foo}$. I think you're overc-omplicating things. Mar 27 '21 at 16:55
• @amWhy My question is only addressing the arrow signs. For example, this sign does not look good. $$\not\Longleftrightarrow$$ Isn't it better to cross in the middle? For example, in my school book, this arrow crosses the middle. Mar 27 '21 at 17:00
• But as I said, your post makes it difficult for users to know how you formatted the mathjax that results in the input you wrote, and I have no time to click, click, click with umpteem pupups, to see your formatting. Note how everything I formatted in my comment, I revealed the mathjax. You might want to consider doing the same. Mar 27 '21 at 17:00
• You're not hearing me, just as you didn't yesterday. I've nothing more to say in response to your last comment. Mar 27 '21 at 17:01
• @amWhy Well. Now it's clear what you mean. I thought it didn't matter as I was mainly asking about the looks part. No problem. I do. Mar 27 '21 at 17:07
• Thanks, @lonestudent, for the edit. One thing I thought of was "I wouldn't use $\require{cancel}\cancel{=}$ = $\require{cancel}\cancel{=}$.but instead would write \neq to get $\neq$. Mar 27 '21 at 19:09
• It takes some time to know various shortcuts, and when they apply. So sometimes it takes a bit of experimenting. It can be exasperating at times. Mar 27 '21 at 19:10
• And \not sometimes works wonderfully, e.g.for "A is not a subset of B" we can write A\not\subseteq B which shows $A \not\subseteq B$. Using A \nsubseteq B renders the same. Mar 27 '21 at 19:13
• @amWhy It seems that you are active in the meta. Not me. You may ignore my inexperience a little bit. :) Mar 27 '21 at 19:14
• I'm sorry if you felt I was ignoring your inexperience earlier. I returned to try and be more helpful. Mar 27 '21 at 19:16
• I'd summarize that if the operator or symbol is long, typically using \require{cancel} \cancel{foo} is your best bet, and the nice thing is, if you use, e.g., \Longleftrightarrow multiple times that all need to be canceled, you only need to write require{cancel} once Mar 27 '21 at 19:22
• \not \longleftrightarrow should be avoided. That's why I posted my last comment. It's a matter of learning which formatting to use in different circumstances. But given the preview window when editing or writing, if what you tried doesn't look like what you want, you've got a few tricks in your pocket to try something else. Mar 27 '21 at 19:26
• No I agree with you, \not\Longleftrightarrow looks terrible. In fact I experimented with it to test it, given your previous question, and it looked aweful. Mar 27 '21 at 19:59

• How are you getting mathjax to render in non-black, and how are you getting Math.SE to have a black background? Also on my computer its very off the mark, cf the footnote of my answer (but I do get nicer results with your code if I use the common HTML math renderer. I just like using the HTML-CSS renderer) Mar 29 '21 at 11:26
• I user Windows 8.1 and the High Contrast Black theme. // Both Google Chrome and Firefox render the stroke centred (modulo the .05em difference mentioned above), as does SumatraPDF when rendering a PDF produced when I do the same thing in TeX. Which browser did you use to produce your image? Mar 29 '21 at 11:36
• I agree that it's correct in TeX as well. To reproduce my output, the easiest way is to find a Mac and run the page on Safari :) I think, if you use the HTML-CSS renderer and install the STIX fonts on your Windows computer, you will get a similar result. I could switch to the common HTML renderer, but (a) I'm used to the appearance of HTML-CSS and (b) anyone using a mac will default to it, so its possible your readers would see it off-center as well. Its less an issue in TeX where the unchanging PDF is usually what you distribute Mar 29 '21 at 11:41
• The wrong position of the slash is a font issue. I haven't found an mathmode font that places the stroke so near the left-hand end as in your screenshot, but with Times as loaded by package txfontsb, it's slightly too far to the left; with Fourier as loaded by package fourier, it's even further to the left. OK -- by using kerns to overlay two glyphs I've avoided "cancel"'s colour bug, but I've created a font-dependency. A question for Tex.SE perhaps? Mar 29 '21 at 11:51
• That sounds correct to me. The STIX fonts in TeX might well reproduce it. And nope, mathjax is specifically off-topic in TeX.SE (hence why there are many posts about Mathjax in math.meta :) ) In TeX, there's a nice package for overlaying symbols that I can't remember the name of. I don't know if it works well with different fonts Mar 29 '21 at 11:55
• its the stackengine package, see for eg tex.stackexchange.com/questions/413333/overlay-symbols Mar 29 '21 at 12:03