S
U
t
(
R
)
W
U
t
(
R
)
G
o
c
h
a
(
R
)
G
e
t
c
h
a
(
R
)
S
U
t
(
R
)
=
⊇
1.
⊇
2.
⊇
3.
W
U
t
(
R
)
=
⊇
4.
∅
5.
G
o
c
h
a
(
R
)
=
∅
6.
G
e
t
c
h
a
(
R
)
=