1
缂栬瘧鍘熺悊鍙婂疄鐜?/p>
2.1
璁惧瓧姣嶈〃
A={a}
锛岀鍙蜂覆
x=aaa
锛屽啓鍑轰笅鍒楃鍙蜂覆鍙婂叾闀垮害锛?/p>
x
0
,xx,x
5
浠ュ強
A
+
鍜?/p>
A*
.
x
0
=(aaa)
0
=
蔚
| x
0
|=0
xx=aaaaaa |xx|=6
x
5
=aaaaaaaaaaaaaaa | x
5
|=15
A
+
=A
1
鈭?/p>
A
2
鈭?/p>
鈥?/p>
.
鈭?/p>
A
n
鈭�?/p>
={a,aa,aaa,aaaa,aaaaa
鈥?/p>
}
A*
=
A
0
鈭?/p>
A
1
鈭?/p>
A
2
鈭?/p>
鈥?/p>
.
鈭?/p>
A
n
鈭?/p>
鈥?/p>
={
蔚
,a,aa,aaa,aaaa,aaaaa
鈥?/p>
}
2.2
浠も垜
={a
锛?/p>
b
锛?/p>
c}
锛屽張浠?/p>
x=abc
锛?/p>
y=b
锛?/p>
z=aab
锛屽啓鍑哄涓嬬鍙蜂覆
鍙婂畠浠殑闀垮害锛?/p>
xy
锛?/p>
xyz
锛?/p>
锛?/p>
xy
锛?/p>
3
12
|=
(xy)3
|
cb
abcbabcbab
=
(abcb)3
=
(xy)3
7
|=
xyz
|
abcbaab
=
xyz
4
|=
xy
|
abcb
=
xy
2.3
璁炬湁鏂囨硶
G[S]
锛?/p>
S
鈭?/p>
=SS*|SS+|a
锛屽啓鍑虹鍙蜂覆
aa+a*
瑙勮寖鎺ㄥ锛?
骞舵瀯閫犺娉曟爲銆?/p>
S => SS* => Sa* => SS+a* => Sa+a* => aa+a*