$4.$ Suppose that each of the following Update operations is applied directly to the database state shown in Figure $5\mathrm{.}6.$ Discuss all integrity constraints violated by each operation, if any, and the different ways of enforcing these constraints.

a$.$ Insert $<mi\; id="EditorElement\_12897701"></mi>$Robert$,$F$,$Scott$,943775543,1972-06-21,2365$ Newcastle Rd$,$ Bellaire, TX$,$ M$,58000,888665555,1>$ into EMPLOYEE.

b$.$ Insert $<mi\; id="EditorElement\_12897839"></mi>$ProductA$,4,$Bellaire$,2>$ into PROJECT.

c$.$ Insert $<mi\; id="EditorElement\_12897894"></mi>$Production$,4,943775543,2007-10-01>$ into DEPARTMENT.

d$.$ Delete the WORKS$\_$ON tuples with Essn $=333445555.$

e$.$ Delete the EMPLOYEE tuple with Ssn $=987654321.$

f$.$ Modify the Mgr$\_$ssn and Mgr$\_$start$\_$date of the DEPARTMENT tuple with Dnumber $=5$ to $123456789$ and $2007-10-01,$ respectively.

g$.$ Modify the Super$\_$ssn attribute of the EMPLOYEE tuple with Ssn $=999887777$ to $943775543.$

$5.$ A courier company maintains up$-$to$-$date information on the processing and current location of each shipped item. To do this, the courier relies on a company$-$wide system described as follows:

$$ Shipped items are the heart of the courier product tracking information system. Shipped items can be characterized by item number $($unique$),$ weight, dimensions, insurance amount, destination, and final delivery date.

$$ Shipped items are received into the courier system at a single retail center. Retail centers are characterized by their type, unique ID$,$ and address.

$$ Shipped items make their way to their destination via one or more standard the courier transportation events $($i$.$e$.,$ flights, truck deliveries$).$ These transportation events are characterized by a unique schedule number type $($e$.$g$.,$ flight, truck$)$ and a delivery route.

Create an Entity Relationship diagram that captures this information about the courier system. Be certain to indicate identifiers and cardinality constraints.