 
Summary: The I/OComplexity of Ordered BinaryDecision
Diagram Manipulation
(Extended Abstract)
Lars Arge #
BRICS ## , Department of Computer Science, University of Aarhus, Aarhus, Denmark
Abstract. We analyze the I/Ocomplexity of existing Ordered Binary
Decision Diagram manipulation algorithms and develop new e#cient
algorithms. We show that these algorithms are optimal in all realistic
I/Osystems.
1 Introduction
Ordered BinaryDecision Diagrams (OBDDs) [6, 7] are the stateoftheart da
ta structure for boolean function manipulation and they have been successfully
used to solve problems from numerous areas like e.g. digitalsystems design, ver
ification and testing, mathematical logic, concurrent system design and artificial
intelligence [7]. There exist implementations of OBDD software packages on a
number of sequential and parallel machines [4, 5, 14, 15]. Even though there
exist very di#erent sized OBDD representations of the same boolean function,
OBDDs in real applications tend to be very large. In [4] for example OBDDs
of Gigabyte size are manipulated in order to verify logic circuit designs, and
researchers in this area would like to be able to manipulate orders of magnitude
