[rules-users] Dynamic generated list

I would like to generate a template that can output rules, as explained in Drools expert user guide at chapter 5.2 ( http://downloads.jboss.com/drools/docs/5.0.1.26597.FINAL/drools-expert/ht... ). My parameters are 2 lists of strings. In some case the list is to be outputted as a "multi restriction", and that is no problem. But, from one of this lists, i need also to generate a collection of strings to then reason over. As an example, suppose the list1 contains 3 productIds, "A","B","C", and the list2 contains "X" and "Y". In the generated rule, i need to check, for example, that: - if a product with id 'X' or 'Y' exists (this part is easy), and - a tuple composed of products from the other list(one "A", one "B", one "C") that individually satisfy some condition exists (this is tough for me) then i will execute my code. I think the generated rule should be something like: when $target: Product (id in ("X","Y")) $list: ArrayList() from ???? #arrayList should contain the parameter values "A","B","C" forall ( $id: String() from $list Product (id == $id, ....here some condition...) ) then ..... The difficult part is to generate the ArrayList dynamically, i don't know how to accomplish that... Any ideas? Is there a better approach than templates, to generate a rule like this? Do you have a suggestion on how the rule could be rewritten to avoid the use of the ArrayList? Thank you in advance Giovanni