[plt-scheme] Renaming +, -, *, /

Hi all,

What's the best way to rename inside a module +, -, *, /, probably
inserting a prefix?
I would use prefix in a require but +,-,* and / belongs to the
mzscheme language so I really can't understand the best way to do
this.

Cheers,
--
Paulo Jorge Matos - pocm at sat inesc-id pt
Web: http://sat.inesc-id.pt/~pocm
Computer and Software Engineering
INESC-ID - SAT Group