[Typo3] Can I evaluate constans in a template?

[Alex]

Hi all,
 
I’m trying to evaluate a constant. Depending on its value, the template
should perform an operation or a different one.
 
Reading the docs, I don’t know how to do it. I have seen an example but it
doesn’t run:
 
[globalVar = LIT:1 = {$constant_to_turnSomethingOn}]
 
This sample does not run in my system.
 
Could anybody help me?
 
Regards,
 
Àlex