If
c
0
|
–
n
c
n
[
r
] for some
n
³
1, then
c
0
|
–
+
c
n
[
r
] or, simply,
c
0
|
–
+
c
n
If
c
0
|
–
n
c
n
[
r
] for some
n
³
0, then
c
0
|
–
*
c
n
[
r
] or, simply,
c
0
|
–
*
c
n
Example:
Consider
a
p
b
c
|–
a
q
a
c
[
1
:
p
b
®
q
a
S
], and
a
q
a
c
|–
a
c
r
c
[
2
:
q
a
®
r
c
R
].
Then,
a
p
b
c
|–
2
a
c
r
c
[
1 2
],
a
p
b
c
|–
+
a
c
r
c
[
1 2
],
a
p
b
c
|–
*
a
c
r
c
[
1 2
]
Sequence of Moves 2/2
1
4
/45