There is a previous thread here, with precise info:
http://www.pprune.org/tech-log/55922...ml#post8929993
Dual inputs are indeed averaged when both sticks are active. (As a software engineer with 40yrs experience I can say this is a thoroughly stupid idea.)
The software cannot therefore be termed an Expert System as it does not mimic the manual controls of old.
No wonder there're so many mishaps when Airbuses are flown by less experienced pilots, or non-English/French speakers.