[Zope] if text: display text else icon with tal

[Roger Erens]

>When you want:
>
>      if cond then XXXX else YYYY
>
>you can use in ZPT:
>
>     <tal:div tal:condition="cond">XXXX</tal:div>
>     <tal:div tal:condition="not:cond">YYYY</tal:div>
>
>To check for existence, you can use "exists: path".
>
>
>Dieter

Could someone expand on *why* the if/then/else construct is not literally 
possible in ZPT?
Is it considered to be already too much logic which the designers of ZPT 
want us to use scripts for?
Or is it an SGML-thing?

Roger