(From this Book-----Database System Concepts (Edition Third)
who can tell me where to find the keys to exercises of this books, thanks!)
the relational database：
give an expression in the relational algebra, the tuple relational calculus, and the domain relational calculus:
1)Find the names of all employees who live in the same city and on the same street as do their managers.
2)Find the names of all employees in this database who do not work for First Bank Corporation.
3)Find the names of all employees who earn more than every employee of Small Bank Corporation.
4)Assume the companies may be located in several cities. Find all companies located in every city in which Small Bank Corporation is located.