Why is Simulation Harder Than Bisimulation?
by
Antonín Kučera,
Richard Mayr,
A full version of the paper presented at CONCUR`02 June 2002, 26 pages.
FIMU-RS-2002-02.
Available as Postscript,
PDF.
Abstract:
Why is deciding simulation preorder (and simulation equivalence)
computationally harder than deciding bisimulation equivalence on
almost all known classes of processes? We try to answer this question
by describing two general methods that can be used to construct direct
one-to-one polynomial-time reductions from bisimulation equivalence to
simulation preorder (and simulation equivalence). These methods can
be applied to many classes of finitely generated transition systems,
provided that they satisfy certain abstractly formulated conditions.
Roughly speaking, our first method works for all classes of systems
that can test for `non-enabledness` of actions, while our second
method works for all classes of systems that are closed under
synchronization.