> So that I ask if the order of selection of objects has or has not importance
> for end intersection (first being selected) :)

I don't think it should make any difference.

The thing that makes a difference is what set you put the "extra" object in.

For instance if the 2 sets are ( 1 2 ) isect ( 3 ) or ( 1 ) iset ( 2 3 ), that can make a difference.

- Michael