I'm trying to write two equations in one line separated by some whitespace. I don't want to add the whitespace manually. Instead I was expecting that & inside an AMS align environment would do the job. However it does not work (and not even \begin{split}). Here's an example:

and here's what I get (exported via ps2pdf):

(In this particular example I didn't use any packages, except for amsmath which, as I understand, is loaded automatically whenever commands like \begin{align} are used)
I fail to understand where is the problem. Any suggestions?



