Improving BDDs manipulation through incremental reduction and enhanced heuristics

The authors present techniques leading to small binary decision diagrams (BDDs) for combinational functions. They propose some new heuristics for computing an initial variable ordering, one of which is shown to represent a significant enhancement over the best ones the authors could find in the literature. Additionally, they introduce a novel incremental method, devised to quickly change the variable ordering intrinsic to these diagrams. They discuss an application of this method involving the reduction of the size of diagrams after their construction. Comparison with previously published results is provided