Active Constraints for a Direct Interpretation of HPSG
  In this paper, we characterize the properties of a direct interpretation of HPSG and present the advantages of this approach. High-level programming languages constitute in this perspective an efficient solution: we show how a multi-paradigm approach, containing in particular constraint logic programming, offers mechanims close to that of the theory and preserves its fundamental properties. We take the example of LIFE and describe the implementation of the main HPSG mechanisms. 
Philippe Blache and Jean-Louis Paquelin (2LC-CNRS, France)