In the examples of the Unary operator, it says:


   let $x:= <node i="3"/> return ?($x/@i) does not raise a type error because the attribute is untyped.

   But let $x:= <node i="3"/> return ?($x/@i+1) does raise a type error because the + operator with an untyped operand returns a double.


This would only be true if the context item is an array, right?  It seems it could be appropriate for a map. 


Likewise for the example that says:

   ?(3.5) raises a type error because the parameter must be an integer.

Perhaps it should say:

   ?(3.5) raises a type error if the context item is an array because the parameter must be an integer.