# Why does MathJax not render in comments on the mobile app? [duplicate]

I sometimes read SX stuff from the app on my android. Today, I found myself reading a question from Math.SX. To my surprise, after a while, I noticed a problem in the comments, which this screenshot records:

(Click image to enlarge)

If you are curious about the question, it is this one. Anyway, as you can see (hopefully the image is not too small, but the dollars seem pretty visible to me) MathJax is not rendered in those comments. THis is very bad, because in this case there isn't this much of complications, and besides, I am very accustomed to LaTeX, but imagine something far more complex (integrals with limits, sums, or the likes) with a user whose LaTeX is bad or not exercised: the comments, thus unrendered, become unreadable. So why is MathJax not rendered in comments whereas it is in the question? And why does this only happen in the app, not the site?

Addendum Is there a more "logical" way of reducing the image besides copying the HTML code from this answer, code placed there by Firelord in an edit, every time I post a screenshot and it is terribly huge? To be extra-clear: this is NOT the question. I'm adding this sentence because it has happened to me that I asked a question, then faced a formating problem while posting it and asked about it as an extra, like here, and got faced with answers addressing only the extra. Please don't.

Update: Yes, the question this has been marked a duplicate of (i.e. this one) is strongly related to it. However, as the titles already show, they are not the same. It is interesting to know this is rather than a , and even more so to know that by tapping on a comment, clicking the vertical ellipse $$\vdots$$ on the top-right corner and choosing render MathJax one can get the comment with rendered MathJax to appear in the middle of the screen; but that doesn't answer why things are that way. Why should MathJax not render in comments in the app? This was my question.

• It looks to me like this question should not be marked as a duplicate. The linked, answered post is reporting the behavior as a bug, and is tagged with status-bydesign. As I'm reading it, this question is instead asking about the rationale for that design - asking Why is it designed to behave this way? Jun 7 '17 at 14:50
• Also: I did find what may be a hint of the answer to the question of "why is it designed this way" in this post by Kasra Rahjerdi. Quoted in part (and very mildly paraphrased): "Adding MathJax / LaTeX to question and answer bodies is really easy, but adding it to comments, question titles, and the question listings is troublesome. Since everything in the app other than the question/answer bodies are native code rather than webviews, this is going to take us a while to try and figure out. At the moment we're putting it on the backburner." Jun 7 '17 at 14:52