Table 6.

Reachable set, antecedent set and their intersection table

	To set z	First set X	Intersection $A=Z\bigcap x$
T1	1,5,10,11,13	1, 12	1
T2	2,4,5,7,8,9,10,11,12,13	2,9,14,17,18,20	9, 2
T3	3,5,10,11,13	3	3
T4	4,5,7,10,11,12,13	2,4,7,8,9,12,14,15,17,18,20	4,12,7
T5	5,10,11,13	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20	5,10,11,13
T6	5,6,10,11,13	6	6
T7	4,5,7,10,11,12,13	2,4,7,8,9,12,14,15,17,18,20	4,12,7
T8	4,5,7,8,10,11,12,13	2,8,9,14,17,18,20	8
T9	2,4,5,7,8,9,10,11,12,13	2,9,14,17,18,20	9, 2
T10	5,10,11,13	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20	5,10,11,13
T11	5,10,11,13	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20	5,10,11,13
T12	4,5,7,10,11,12,13	2,4,7,8,9,12,14,15,17,18,20	4,12,7
T13	5,10,11,13	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20	5,10,11,13
T14	2,4,5,7,8,9,10,11,12,13,14	14	14
T15	4,5,7,10,11,12,13,15	15	15
T16	5,10,11,13,16	16	16
T17	2,4,5,7,8,9,10,11,12,13,17	17	17
T18	2,4,5,7,8,9,10,11,12,13,18	18	18
T19	1,5,10,11,13,19	19	19
T20	2,4,5,7,8,9,10,11,12,13,20	20	20

the number represents an element, for example, 2 represents the second element