Analyzing Declarative Semantics of Logic Programs by Dmitri Boulanger GMD FIRST, Berlin, Germany Abstract Deductive databases and constraint systems have a transparent declarative semantics, which enables to read and to understand such programs ignoring their execution algorithms. An interactive toolkit, which is aimed at such "understanding", is presented. It enables generation of precise descriptions of the goal-relevant correct answers. Its ultimate goal is a problem-specific op- timization, which can be derived from such descriptions. A flexible interface is used to specify re- quired details of descriptions. The toolkit is reasonably efficient even if a fine-grained description is required.