Named function reference
If a function is builtin or declared in a prolog, in the same module or imported, then it is also possible to build a function item by referring to its name and arity.
Example 39. Named function reference
declare function local:sum($x as integer, $y as integer) as integer
{
$x + 2
};
local:sum#2
Result. (a function items)
The semantics of named function reference expressions follow the W3C specification.
Figure 26. NamedFunctionRef
