> I've just thought that by the same token there are dangling 
> sequence items
> in:
> 
> for $item in $items return
>   expr1, expr2
> 
> and in
> 
> if (expr) then
>   expr1
> else
>   expr1, expr2
> 

Yes, I agree, the low operator precedence of "," relative to expressions
like "for" and "if" is counter-intuitive and a rich source of coding errors.
Explicit algol68-style closers (end-for, end-if) would have solved the
problem but they don't appear to be a popular solution.

The more you use explicit type declarations, of course, the more likely such
errors are to show up at compile time.

Michael Kay
http://www.saxonica.com/