What is all the information about faculty?
select * from faculty
Of those, which are in the computer science department?
select * from department as t1 join faculty as t2 on t1.dno = t3.dno join member_of as t3 on t2.facid = t3.facid where t1.dname = "Computer Science"
What are their last names?
select t2.lname from department as t1 join faculty as t2 on t1.dno = t3.dno join member_of as t3 on t2.facid = t3.facid where t1.dname = "Computer Science"