I want to keep only 1 fact with id=="aaaa". But this is not working:
rule "leave only one"
when
$removeUs : java.util.List(size>1)
from collect(Fact(id=="aaaa")
then
size = $removeUs.size();
for (int i=1; i < size; i++) {
retract($removeUs.get(i));
}
end