Answer Happy

Draw an extended ER model for the example scenario
provided. using this extended notation.
Draw a TREND data model for the following description:
Flight is an entity type whose objects will always be a
flight.
Client is an entity type whose objects will always be a
client.
Traveller is a client.
Previous-customer is a client.
VIP-customer is a client.
Each traveller is not a traveller for some time.
Each previous-customer is not a previous-customer for some
time.
Each VIP-customer is not a VIP-customer for some time.
A client may also become a traveller.
A client may also become a VIP-customer.
Each traveller must evolve to a previous-customer ceasing
to be a traveller.
A previous-customer may also become a traveller.
A previous-customer may also become a VIP-customer.
Each VIP-customer was already a previous-customer.
Each VIP-customer was already a traveller.
A traveller books a flight A traveller pays for a flight.
A previous-customer took a flight.
Each traveller books a flight will be followed by traveller pays
for flight after exactly 3 days, terminating the traveller books a
flight relation.
Each previous-customer took a flight must have been
preceded by traveller pays for flight, and terminating that
traveller pays for flight relation.
Each object in entity type client having attribute company
does not have a company at some time.
Each object in entity type flight having attribute delay has
delay at all times.
Once the value for arrival time is set, it cannot change
anymore