Graph-Based Representations of Discrete Functions

BDDs are now commonly used for representing Boolean functions because of their efficiency in terms of time and space. There are many cases in which conventional algorithms can be significantly improved by using BDDs. Recently, several variants of BDDs have been developed to represent other kinds of discrete functions, such as multi-valued functions, cube sets, or arithmetic formulas. These techniques are useful not only for VLSI CAD but also for various areas in Computer Science. In this chapter, we survey the techniques of BDD and its variants. We explain the basic method of BDD manipulation, and show the relationships between the different types of BDDs.