Rendered propety valid expressions?

[John Conner]

I have just started with JSF and have been playing around with el 
expressions in the rendered property of components.  Is there someplace 
that explains what is valid/invalid as an expression for this property?

Specifically is it possible to:
1. Use an and condition like
     rendered="#{mb.propertyBoolean1 && mb.propertyBoolean2}"

2. Is it possible to compare to an enum value
     rendered="#{mb.enumValue == a.b.c.EnumClass.ENUM_VALUE}"

3. Use a complex call like
     rendered="#{mb.someFunction(mb2.value1)}"


Thanks,
- JC