{za'u re'u} seems very far-fetched: (greater than ?)-th-time (according to the CLL).
This could be applied not only to "one more time", but also to all next times (times with ordinal numbers greater than current).
I have carefully looked through the chapter 18 of the CLL and to my surprise haven't found any cmavo with the following meanings:
"??? preceding ordinal" (like the operator -- of the C)
"??? succeeding ordinal"(like the operator ++ of the C)
In Peano axioms of arithmetics (http://en.wikipedia.org/wiki/Peano_axioms) the precedence operator is the main tool to construct all natural numbers.
This operator, if had existed, could easily be used to construct "once more" or "again".
mi'e .ianis.