wEach ADT description consists of two
parts:
Data:
nThis part describes the structure of the data used in the ADT in an informal way.
Operations:
nThis 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.