[rules-users] join array and object

Folks, I have a Parent and Children, but need to do aggregate function on collection of Parent WITH Children, to find the minimum expiration date on them, how can I create in LHS expression a collection of Parent WITH Children? Like: rule ... when p : Parent() c : Date() from accumulate( Child( d: date) from ($p.children and $p), min($d) ) // ?? what can I use to join collection of $p.children with $p to get another collection with them all ?? then .... end Thanks! -Sergey ********************** ** LEGAL DISCLAIMER ** ********************** This E-mail message and any attachments may contain legally privileged, confidential or proprietary information. If you are not the intended recipient(s), or the employee or agent responsible for delivery of this message to the intended recipient(s), you are hereby notified that any dissemination, distribution or copying of this E-mail message is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete this E-mail message from your computer.