[rules-users] Lists with from clause in 3.1M1

[kchantzara at costamare.com]

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