MathJax multiple subscripts not processed

[cuihtlauac]

This:

$$F_n=F_{n-1}+F_{n-2}$$

fails to be displayed if added in the LaTex using MathJax exemple.

[wookayin]

See also #336. It is a marked bug which is not resolved yet.

A workaround: anaderi@b0d04955.

[SWotherspoon]

But it works if you surround it with backticks. If you use the "(" format rather than "$" you can easily fix with a search and replace.

`$$F_n=F_{n-1}+F_{n-2}$$`

[piojanu]

I can't understand, how to exactly apply work around?