Alan is here so he can tell us! Please Alan.
I actually don't think that Alan's $ signs did anything.
If you are working with LaTex away from a forum you need to put $ signs around the maths made parts.
On forums this is effectively done for you. I know Alan writes a lot of his Latex and coppies it over. He probably didn't here but the $ signs would just be a habit that he is in.
I don't know why he has put the 2 extra dollar signs at the front. I think he would b e happy to tell us though.
This was your code Alan
$$$\int dx$
$$$\int dx$$$
-------------------------------------------------------------------
The other day Heureka used something else instead of \mbox{}
It had the same purpose. I cant remember what it was but it would be referred to in the LaTex thread for sure. I have been faily consciencious about updating and adding to the LaTex thread. Although I will admit that it is a bit of a mess. 