Notation of ADT
Each ADT description consists of two parts:
Data:
n This part describes the structure of the data used in
the ADT in an informal way.
Operations:
n This part describes valid operations for this ADT,
hence, it describes its interface. We use the special
operation constructor to describe the actions which
are to be performed once an entity of this ADT is
created and destructor to describe the actions
which are to be performed once an entity is
destroyed. For each operation the provided
arguments as well as preconditions and
postconditions are given.