Retrieve the names of all employees in department 5 who work more than 10 hours per week on the âProductXâ project.
p10ssn â (Π essn (Ï hours > 10 (works-on |X| pno = pnumber(Π pnumber (Ï pname = âProductXâ (project))))
Π lname, minit, fname (Ï dno = 5 (employee |X| ssn = essn (p10ssn)))
select lname, minit, fname
from employee, works-on, project
where ssn = essn AND pno = pnumber AND
dno = 5 AND hours > 10 AND
pname = âProduct Xâ;