An example of the rule file format is shown in
Figure 
. By looking at the example figure, the
formal description given below should be easier to understand. We give
the EBNF grammar for the rule file in
Figure . ::= means production, means one or more repetitions, means
optional, '' denote strings, () are used for grouping and denote a choice. Integer, RealNumber and String
is used as terminal symbols.
At the top of the rule file, there should be a few lines which give the number of objects and attributes in the training set, together with the distribution of the decision values. Then all the rules are listed together with lattice information. This is done with 2 lines starting with ``RBaseNo'' and ``Attrib'' above their corresponding rules, before 2 new lines with this information and rules follow and so on. At the end of the file, a list of all default rules and blocking rules may be present (since this is given from RGEN), but these rules are not used.
Figure: Example of RGEN rule file.
Figure:
Grammar of RGEN rule file in Extended Backus-Naur form.