关系模型基于谓词逻辑和集合论，为数据库管理提供了坚实的数学基础。
The psychologist must be a neutral observer.
The truth about a person is often found in what they tried to hide.
Authenticity in design comes from honesty in materials and process.
通过读书，除了找到自己我们别无所获。说来也怪，我们还是欣喜若狂，还把作者称为天才。