1. Introduction: The addition of a characteristic to a basic subject idea or an isolate idea leads to the addition of an array. The addition of an array implies the addition of a further division of a basic subject or an isolate idea as the case may be. Any isolate idea taken along with its succession of sub isolates is also an isolate idea. The succession of the isolate idea from the first to the last reached in this process is denoted by the term “chain of isolate idea”. A chain may similarly be formed in respect of basic subject idea.
2. Array: The series of co-ordinate subdivision which are obtained by dividing a class or a division according to a single characteristic. Each co-ordinate division in array should exclude all the others and the whole array should be exhaustive of the context of the class. The order of the division in an array should be that deemed most helpful to users.
3. Chain: The successions of division subordinate one to another expressing the relation. “A includes B which in turn includes C (or conversely c is a part of B which is a part of A) constitute a chain of or it may also be defined as a hierarchy of term each containing or including all which follow it in the same series.
4. Examples: Asia, India, Assam, Kamrup, Guwahati is a chain of isolate idea.