Hello, I have asserted one ArrayList<Cylinder> into my working memory and I am using the 'from' clause to iterate over the items of the list and fire the rule accordingly. i.e.: rule "Firing Pressure Less Than Min" agenda-group "cylinder" salience 22 when $cylinders: ArrayList() $cylinder : Cylinder(pressureValue < Pressure.MIN_VALUE) from $cylinders then System.out.println("The FP of Cyl xxx is Lower than Min Possible."); end I would like to make the following questions: a) Is it possible to get the index of the item in the list for which the rule fired; Lets say that I would like to do that without adding extra fields in the Cylinder class. b) If i had a second ArrayList<Cylinder> in my working memory would I be able to iterate over the two lists simultaneously and compare values for corresponding items in the LHS; c) Can I use the 'from accumulate' clause over an ArrayList instead of individual objects asserted into the working memory; My apologies for the multiple questions in one mail. Thank you in advance for any help, Katerina