[XQuery] 3.8 FLWOR Expressions: tuple stream

XQuery 1.0: An XML Query Language
W3C Working Draft 12 November 2003

3.8 FLWOR Expressions

(1)
You should clarify how the "tuple stream" relates (or doesn't) to the
dynamic environment.

(2)
Given the example "tuples" in 3.8.1, such as
   ($i = 1, $j = 3)
it seems clear that they're not really tuples (or certainly not best
described as tuples). For instance,
   ($j = 3, $i = 1)
would (properly speaking) be a different tuple, and yet it would appear
to have exactly the same effect as far as XQuery is concerned.

So in fact, these things are best described as *mappings* (from
variables to values), not tuples.

-Michael Dyck