Laurent Fribourg, Hans Ols<e'n:
Proving Safety Properties of Infinite State Systems by Compilation into Presbur  ger Arithmetic.
CONCUR'97, 1997.

Francisco Bueno, Pierre Deransart, Wlodek Drabent, Gerard Ferrand, Manuel Hermenegildo, Jan Maluszynski, German Puebla:
On the Role of Semantic Approximations in Validation and Diagnosis of Constrain  t Logic Programs.
In Proceedings of AADEBUG'97 (The Third International Workshop on Automated Deb  ugging), 1997.

Laurent Fribourg, Hans Ols<e'n:
Decompositional Approach for Computing Least Fixed-Points of Datalog Programs w  ith Z-Counters.
Journal of Constraints (submitted), 1997.

Johan Boye, Wlodek Drabent, Jan Maluszynski:
Declarative Diagnosis of Contraint Programs: an Assertion Based Approach.
In Proceedings of AADEBUG'97 (Third International Workshop on Automated Debuggi  ng), 1997. (Linköping, Sweden).

Johan Boye, Jan Maluszynski:
Directional Types and the Annotation Method.
Journal of Logic Programming, 33(3), 1997. (The postscript gives an early versi  on).