Hello,
what I want to do, is to calculate on object's attributes in WHEN section of rule. Can I do it?

For example:

class CObj
{
              private int k;
              private int n;

              // setters and getters
}

Now what I want to do is:

rule "r1"
    when
        p : CObj ( k + n <= 1000)
    then
        System.out.println("We love Drools :)");
end

Why can't I construct conditions like in Java, or C++ (with calculations in conditions)? How can I achieve my goal?

Thx,
Tom.