Groups Promotion Rules Question

[PPlanet]

I have a few of these groups promotion rules in place but I've never done a time-based one. Now I'd need to do the following:

Members who belong to primary group A, with a post count of 100 and who have posted in the last week, get a secondary group assigned.

Those same members must lose the secondary group when they haven't posted in the last week. (And they recover it when they post and so on)

So, is it correct to think that I need 2 separate rules?

One assigns the secondary group to members of primary group A with a post count of 100 and who have posted in the last week (or 7 days).

The other, removes the secondary group to members who haven't posted in the last week.

Or, is it the first rule enough to do both things at once? (Somehow I doubt it though)