>>>>> "Dimitre" == Dimitre Novatchev <dnovatchev@xxxxxxxxx> writes:


    Dimitre> Or be prepared for all kinds of a nasty surprise
    Dimitre> following the fact that the value of
    >>
    Dimitre> my:f($x) is my:f($x)
    >>
    Dimitre> is generally not guaranteed to be true()
    >>  It isn't, as if either function returns an atomic sequence,
    >> you get a type error.


    Dimitre> Sure, I must have added that my:f() is of type node()*.

Not really. My comment was off the ball.
Since $x may raise an error anyway.
To be pedantic, my:f($x) is my:f($x) should always evaluate to true()
in the absence of errors. But that can be taken as read.
-- 
Colin Adams
Preston Lancashire