为什么这个类层次结构不能流畅映射工作？

What's wrong with my mapping shown below? Is this a problem with GeneratedBy.Foreign()? How should I use it cause my PK in UserTable(UID) is also the FK which refers to PersonTable PK(PID). I get the Duplicate class/entity mapping consoleMappingTest.SystemUser error. what do you suggest(be sure to look at database structure- no way to change it). thanks.What's wrong with my mapping shown below? Is th