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
Apa
bc
|–
A
B
q
bc
[
1
:
Apa
®
Bq
], and
A
Bqb
c
|–
A
BCr
c
[
2
:
Bqb
®
BCr
].
Then,
A
Apa
bc
|–
2
A
BCr
c
[
1 2
],
A
Apa
bc
|–
+
A
BCr
c
[
1 2
],
A
Apa
bc
|–
*
A
BCr
c
[
1 2
]
Sequence of Moves 2/2
28/50