I experience some strange issue trying to use formulas in Codeforces blog post.
The steps to reproduce: go to your profile, press "Write new entry", place dollar sign character, then sh (two characters), then dollar sign character into content field (total four characters) and then press Preview button.
Expected behaviour: italized sh in preview.
Observed behaviour: Unable to parse markup [type=CF_TEX] message in preview.
What am I doing wrong and what to do about it? I tried to post an article containing many formulas and was not able to do it. I reduced it to the smallest test case. Several other two-letter combinations produce a strange result too.
Yeah, something is crapped. In particular, I can't correct my mistake here: http://codeforces.com/blog/entry/23624?#comment-279143 because "\sin \alpha = Im(e^{i \alpha})" gives me "Unable to parse markup [type=CF_TEX]" (whereas Re parses correctly ._.) and I also needed to write "Im" and "Re" in next post without dollars, because both of them were giving errors.
Previously generated formulas were cached, so they just worked. Probably one day something got broken with TeX installation (I don't know, executable removed?) and no new formulas can be generated anymore.