The DATA DICTIONARY provides definitions of important data items and relationships.


  • Each Continent and Ocean is assigned a unique 2 digit ID number.

    class Continent object
       Continent_ID : integer (0..99)

  • Each city is assigned a compound two-part identifier. The first part simply duplicates the city's continent ID (this is redundant; cities are considered immobile. Or are they?). The second part is a two digit number assigned at generation time, and unique among cities on that continent.

    class City object
       Continent_loc : Continent ;
       City_ID : integer(0..99)

  • Each piece is assigned a compound multi-part identifier. The first two parts identify the continent and city of manufacture; the next part describes the piece type; and the final part is a number assigned sequentially upon production. Collectively, these parts are known as the piece's "license plate".

    class Piece_ID : object
       Location_of_Manufacture : City ;
       Piece_Type : integer(0..99) ;
       Production_Number : integer(0..9999)

The Piece_Type above is troubling: how specific should it be? As new pieces are defined, are they given corresponding new Piece_Types? If so, does the _customization_ of an existing Piece_Type mandate the creation of a new Piece_Type? The underlying question: what will this field be used for? Possibly Piece_Type need only distinguish (air,sea,land).