Catalog Price Rule and sub category

[hanhoe]

Hello,

I have this categories:

1. root
   1. cat 1
   2. cat 2
      1. cat 3
      2. cat 4
   3. cat 5

I have one product in "cat 4"

I have 2 catalog price rules:

1. 20% Discount on cat 1
2. 80% Discount on cat 4

So all products in cat 1 and child categories should have 20% .. but cat 4 should get 80%

With my rules, he calculate for cat 4:
price - 20% - 80%

Is the price 100$ then he show the product in cat 4 16$

But it should 20$

How can I reach this?
And I dont want to set for each category a price rule ... the rule should be applied also for the childs ... bit not, when a child has a new rule.

Thank you!