Thanks. I got total 12 cases. This time, we followed the order.

來源: 於 2010-10-17 14:24:19 [舊帖] [給我悄悄話] 本文已被閱讀：次

1) OOOA   OOAO

2) OORA   OROA

3) OOAA   OAOA

4) ORRA   ORAR

5) ORAA   OARA

6) OAAA  

7) RRRR

We say yes for isomorphism.