Index constraint type for interesects() and disjoints()

In OptaPlanner, we would like to be able to index the following operation:

$a1: A()
$a2: A($a1 != this, this.collectionOfA intersects $a1.collectionOfA)

Likewise, the following operation should be indexed:

$a1: A()
$a2: A($a1 != this, this.collectionOfA disjoint $a1.collectionOfA)

"intersects" is true when both collections share at least 1 element.
"disjoint" is true when both collections share no elements.

We only need support for this on the executable model level, although DRL support would be cool too.