# Latex not rendering properly

I recently edited this person's question here. However the \begin{eqnarray*} command does not seem to be functioning correctly as the two rows in the array are now in 1. Can someone help to look into this? Furthermore while typing up my answer down below to the question yesterday, as I was typing the words on the page were flickering. What is happening here?

• Huh, that's odd. That bug should've been fixed before. (It is that problem with \ being parsed by MarkDown again. For some reason the $$ is not doing its job in preventing that.) – Willie Wong Mar 29 '12 at 21:54 • @WillieWong Do you know about why the words are flickering when I type up an answer? – user5783 Mar 29 '12 at 21:58 • No idea. That may be browser dependent, since I don't see that. – Willie Wong Mar 29 '12 at 22:11 ## 2 Answers You need to use three slashes instead of two at the end of each row for reasons I don't completely understand. • you shouldn't though. That bug should've been fixed already. See: e.g., the test answer I just posted. – Willie Wong Mar 29 '12 at 21:56 • @QiaochuYuan That's fixed it. But seems odd because in typing up a latex document I only need two slashes! – user5783 Mar 29 '12 at 21:57 • @Benjamin: LaTeX isn't the only thing at work on SE. SE also processes Markdown, and sometimes the two interfere with each other (especially annoying because there's some subtlety like the main site processes Markdown before LaTeX but the preview does it the other way around). – Qiaochu Yuan Mar 29 '12 at 21:59 The problem is that you placed A inside the \text{...} element, which breaks the escape mechanism SE uses to detect \\ inside math environments. A work around is to put the A outside \text and remove the extra s. The one from the post breaks:$$\begin{align} A^0 &= \bigcup \text{All open sets contained in $A$} \ \overline{A} &= \bigcap \text{All closed sets containing $A$} \end{align} $$But can be fixed by a workaround by not using nested \text and $$ expressions:

\begin{align} A^0 &= \bigcup \text{All open sets contained in} ~A \\ \overline{A} &= \bigcap \text{All closed sets containing} ~A \end{align}

• It looks to me like the difference between your examples is that in the breaking example there are already other slashes in the row. – Qiaochu Yuan Mar 29 '12 at 22:00
• @Qiaochu: I thought that at first. But I am convinced now that the reason is that there are other \$s in the row. – Willie Wong Mar 29 '12 at 22:11
• With the new preview code installed a week ago, the nested dollar sign should not be a problem. I have tested it below and it previews fine for me, but I didn't save the answer, so perhaps there is a problem later on in the pipeline. I wonder if the code that puts the final answer into the page also needs to be modified to handle the math delimiters properly (like the changes I made to the preview code). – Davide Cervone Apr 2 '12 at 14:30
• @Davide: the preview works, yes. The final output, as you can see above, doesn't. So I think something in the pipeline still needs to be modified. – Willie Wong Apr 3 '12 at 12:11
• OK, that's not my code, but I'll pass along the issue to those who handle it. The two certainly need to be in synch. – Davide Cervone Apr 3 '12 at 17:54