Employee=(ID, name, position, officeN, phoneN,age)// assume the name is unique.

Committee =( title, meetingDate, startTime, endTime, location)// You may use <,>,=,!= between dates and times.

Membership= ( ID, title, task) // task = member or chair

5. List the name of every employee who does not have a phone number

6. List the title of every committee on which both Sandy Liu and Barry Smith are serving.