+/**
+* @file irprog.h
+*
+* ir representation of a program.
+*
+* @author Goetz Lindenmaier
+*
+* This file defines a construct that keeps all information about a
+* program:
+* - A reference point to the method to be executed on program start.
+* - A list of all procedures.
+* - A list of all types.
+* - A global type that contais all global variables and procedures that do
+* not belong to a class. This type represents the data segment of the
+* program. It is not the base class of
+* all classes in a class hierarchy (as, e.g., "object" in java).
+* - A degenerated graph that contains constant expressions.
+* - interprocedural outs state.
+* - a flag indicating validity of the interprocedural representation.
+* - the output file name
+*/