[rules-users] how "exists" works exactly?

Hi all, I don't know exactly why I have a problem in my "exists" function. I've tried many different ways, but it does not work. Anybody could help me, please? I have the following rules: *rule "diff" when $var1: EReference(name == "employee") $var2: EClass(name == "Company", EAllReferences contains $var1) not (exists( EPackage(EClassifiers contains $var2 ) )) then insertLogical(new IntConstraintOccurrence("diff", 10)); end rule "ClassesNotReferenced" when $q1 : EClass(); $q2 : EPackage(EClassifiers contains $q1); not( exists ( EReference(EType == $q1) )); then insertLogical(new IntConstraintOccurrence("ClassesNotReferenced", 1, $q1)); end* and in my facts (and my EPackage) I have 4 instances of EClass "Company" with a EReference "employee", and another EClass "Person". I still have a "move" that removes EClasses in my Drools Solver. I need to have only one classe "Company" after processing. But it removes only the EClass "Person", when it was supposed to remove one EClass "Person" and 3 ECLasses "Company". Leaving one EClass "Company" in the end. The problem is: when Drools tries to remove a EClass "Person" it thinks that the EClass "Company" does not exists. But in fact there are 3 others. Any clue about it, please ? Thanks Bests regards Antonio