Please note, the file you are viewing is the source code of a template, not the merged result from a php script (this server does not do scripting).

You are likely seeing this as rendered html. One object of TNT templating is to be able to view your templates as examples of what they will eventually look like. In any case, Use View:Source (or equivalent) to view the full source code text of this example template.

This paragraph contains two variables, $a={+$a+}, and $b={+$b+}.