Logic List Mailing Archive

Postdoctoral positions in reachability problems, Bordeaux & Cachan (France)

The ANR project REACHARD proposes several PostDoc positions on
reachability problems for counter systems, including vector addition
systems and related models. Each position can take place either
- at LaBRI, University of Bordeaux, France (http://www.labri.fr/), or
- at LSV, ENS Cachan, France (http://www.lsv.ens-cachan.fr).

See also http://www.lsv.ens-cachan.fr/Projects/anr-reachard/.

** HOW TO APPLY **

Candidates for PostDoc positions should  send to anr-reachard@lsv.ens-cachan.fr
a detailed curriculum vitae, a reference letter by the PhD supervisor and a
link to the PhD thesis.


** THE PROJECT REACHARD IN A NUTSHELL **

Many standard verification problems can be rephrased as reachability
problems, and there exist powerful methods for infinite-state systems;
see e.g. the theory of well-structured transition systems.  However,
obtaining decision procedures is not the ultimate goal, which we
rather see in crafting provably optimal algorithms---required for
practical use.  In the ANR project REACHARD, we focus on algorithmic
issues for the verification of counter systems, more specifically to
reachability problems for vector addition systems with states (VASS)
and related models.

More specifically, the main objective of the ANR project REACHARD is
to propose a satisfactory solution to the reachability problem for
vector addition systems, that will provide significant improvements
both conceptually and computationally.  Recent breakthroughs on the
problem and on related problems for variant models should also allow
us to propose solutions for several extensions, including for instance
VASS with one zero-test or branching VASS.  Furthermore, the goal is
to take advantage of the new proof techniques involving semilinear
separators designed by J. Leroux in order to design algorithms that
are amenable for implementation.  We propose to develop original
techniques in order to solve the following difficult issues:

- to understand the mathematical structure of reachability sets and
relations in vector addition systems,

- to develop new techniques for the computational analysis of
reachability problems that are verification problems connected in
some way to the reachability problem for VASS or their extensions,

- to design algorithms, most probably on the lines of Karp & Miller
algorithms, plus relating flattening methods and semilinearity,

- to widen the scope of our analysis to models richer than VASS,
including models with restricted zero-tests or with branching
computations.

** FURTHER INQUIRY **

Any further inquiry should be sent to anr-reachard@lsv.ens-cachan.fr.