Weizmann Logo
ECCC
Electronic Colloquium on Computational Complexity

Under the auspices of the Computational Complexity Foundation (CCF)

Login | Register | Classic Style



REPORTS > DETAIL:

Revision(s):

Revision #1 to TR98-001 | 19th January 1998 00:00

The Nonapproximability of OBDD Minimization Revision of: TR98-001

RSS-Feed




Revision #1
Authors: Detlef Sieling
Accepted on: 19th January 1998 00:00
Downloads: 1030
Keywords: 


Abstract:

The size of Ordered Binary Decision Diagrams (OBDDs) is
determined by the chosen variable ordering. A poor choice may cause an
OBDD to be too large to fit into the available memory. The decision
variant of the variable ordering problem is known to be
NP-complete. We strengthen this result by showing that for each
constant c>1 there is no polynomial time approximation algorithm
with the performance ratio c for the variable ordering problem
unless P=NP. This result justifies, also from a theoretical point
of view, to use heuristics for the variable ordering problem.


Paper:

TR98-001 | 17th December 1997 00:00

On the Existence of Polynomial Time Approximation Schemes for OBDD Minimization





TR98-001
Authors: Detlef Sieling
Publication: 6th January 1998 18:39
Downloads: 1167
Keywords: 


Abstract:

The size of Ordered Binary Decision Diagrams (OBDDs) is
determined by the chosen variable ordering. A poor choice may cause an
OBDD to be too large to fit into the available memory. The decision
variant of the variable ordering problem is known to be
NP-complete. We strengthen this result by showing that there in no
polynomial time approximation scheme for the variable ordering problem
unless P=NP. We also prove a small lower bound on the performance
ratio of a polynomial time approximation algorithm under the
assumption P\neq NP.



ISSN 1433-8092 | Imprint