Table A8.

Level partitioning of the drivers.

Drivers	Reachability set	Antecedent set	Intersection set	Level
D2	2	1,2,6,7,10,11,13,14,15,16,18,20	2	Level 1
D5	5	5,6,7,10,14,18	5	Level 1
D1	1,11,13	1,6,7,10,11,13,14,15,16,18,20	1,11,13	Level 2
D13	1,13	1,7,10,11,13,15,16,18,20	1,13	Level 2
D11	11,16	7,10,11,15,16,20	11,16	Level 3
D7	7,10,16,20	6,7,10,14,16,18,20	7,10,16,20	Level 4
D10	7,10,16,20	7,10,14,15,16,18,20	7,10,16,20	Level 4
D6	6,18	6,14,15,16,18,20	6,18	Level 5
D18	6,16,18,20	6,14,15,16,18,20	6,16,18,20	Level 5
D16	16,20	14,15,16,20	16,20	Level 6
D20	14,16,20	14,15,16,20	14,16,20	Level 6
D14	14,15	14,15	14,15	Level 7
D15	14,15	14,15	14,15	Level 7