xslt function documentation

Hi, I'd like to know if someone out there knows a good tutorial or some simple examples about how to use xslt functions. The manual says the xslt ext is in experimental phase and so the documentation lacks of even good examples or description of the function arguments. I've already read Sablotron's documentation, but some help will be appriciated, especially for xslt_transform(). Papp Gyozo - pgerzson@freestart.hu