Note about Undeeded Patterns

Restrictions are not needed in this rule.

rule "Pattern possibility that is always true"
when
a: Restriction()
b: Restriction()
$pp: SubPattern()
Opposites(
(
left == a && right memberOf $pp.items
) && (
left == b && right memberOf $pp.items
)
)
then
insert( new AlwaysTrue( $pp, a, b ) );
end

Because it could be simply written as:
when
$pp: SubPattern()
Opposites( $left: left memberOf $pp.items &&
$right: right memberOf $pp.items )
then
insert( new AlwaysTrue( $pp, $left, $right ) );
end