R(Si)

Q(Si)

R(Si)∩Q(Si)

S1

1,3,4,5,7,8,9

1

1

S2

2,3,4,5,7,8,9

2

2

S3

3,4,5,7,8,9

1,2,3,4,5,6,7,8,9

3,4,5,7,8,9