Hi, John.  Jeremy Steward has reported and fixed a bug in
the SRFI 117 document:

Jeremy Steward <xxxxxx@github.com> writes:

| I noticed a typo (more just missing text) in the procedure
| signature of list-queue-update-right, so I added the
| missing parameter to the procedure definition.  This
| doesn't change anything, but makes it so the signature
| matches the description below it as well as the
| implementation.

Here's the diff:

-<tt>(list-queue-unfold-right </tt><var>stop? mapper successor seed</var><tt>)</tt>
+<tt>(list-queue-unfold-right </tt><var>stop? mapper successor seed</var> [ <var>queue</var> ]<tt>)</tt>

I'm going to apply this fix now since it's clearly right.