Some heuristics for generating tree-like FBDD types

Reduced ordered binary decision diagrams (OBDD's) are nowadays the state-of-the-art representation scheme for Boolean functions in Boolean manipulation. Recent results have shown that it is possible to use the more general concept of type consistent free binary decision diagrams (FBDD's) without giving up most of the useful computational properties of OBDD's, but possibly reducing the space needed for computations. The FBDD types used in this approach which generalize the OBDD's orders have significant impact on the space required like orders have. In the paper we start to describe some heuristics for deriving tree-like FBDD's types. The experimental results obtained demonstrate clearly that the FBDD-approach is not only of theoretical interest but also of practical usefulness even with such easy structured tree-based FBDD types produced by the developed heuristics. (orig.)Available from TIB Hannover: RR 1843(94-03) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman