1. core:forEach - this function is documented as parsing over an XPath
expression. Actually, it parses over a list of things. xml:forEach parses
over an XPath expression.
2. xml:set - This function creates a variable of type List or Element,
than type document. Thus, the variable created from xml:set can be
used from the other xml library functions, but it cannot be used directly
by most functions in other libraries, which accept Document variables.
3. core:invoke -
current: A tag which creates a new object of the given type
correction: A tag which calls a function in an object instantied by core:new
4. core:invokeStatic is not documented on web page (I think that if you
just regenerate the web documentation, this will be fixed automatically)