Modify the ERD you created in Problem $25$ to eliminate the problems created by the use of

synonyms. $($Hint: Modify the CHARTER table structure by eliminating the CHAR$\_$PILOT and

CHAR$\_$COPILOT attributes; then create a composite table named CREW to link the CHARTER and

EMPLOYEE tables. Some crew members, such as flight attendants, may not be pilots. That's why

the EMPLOYEE table enters into this relationship.$)$

Create the relational diagram for the design you revised in Problem $27.$

You want to see data on charters flown by either Robert Williams $($employee number $105)$ or

Elizabeth Travis $($employee number $109)$ as pilot or copilot, but not charters flown by both of them.

Complete Problems $29,30,$ and $31$ to find this information.