Representing knowledge base by using decision tree
approach basically requires several definition processes.
Firstly, defining a problem domain will be the main concern.
Secondly, defining facts or symptoms that are probably appear
in identification process as a decision node. Thirdly, defining
inference as the diagnosis result of several facts or symptoms
that appears as a leaf node. Fourthly, defining basic rule
elements that are illustrate the relation between nodes as a
decision tree representation.