A set of executable specifications and efficient implementations of backtrackable state persisting over the current AND-continuation is investigated. At specification level, our primitive operations are a variant of linear and intuitionistic implications, having as consequent the current continuation. On top of them, we introduce a form of hypothetical assumptions which use no explicit quantifiers and have an easy and efficient implementation on top of logic programming systems featuring backtrackable destructive assignment, global variables and simple specifications in term of translation to side-effect free Prolog. A variant of Extended DCGs handling multiple streams without the need of a preprocessing technique, Hidden Accumulator Grammars (HAGs), are specified in terms of linear assumptions. For HAGs, efficiency comparable to that of preprocessing techniques is obtained through a WAM-level implementation of backtrackable destructive assignment, supporting non-deterministic execut...

With huge amounts of information connected to the global information network (Internet), efficient and effective discovery of resources from the "global information base" has become an imminent research issue, especially with the advent of the Information Highway. This article proposes the use of novel Artificial Intelligence and Database techniques (Assumption Grammars, Concept Hierarchies, Multi-Layered Databases, Intelligent Agents) for intelligently searching information pertaining to a specific industry on the web.

Introduction to ViSe2 multi-agent cooperation system; (2) system supports, which indicate necessary system requirements to run the ViSe2 agents; (3) ViSe2 configurations, which show the way of making a ViSe2 agent work in your UNIX system, and the cooperation establishment; and (4) how the ViSe2 system works. COPYRIGHT of the Virtual Secretary 2 software belongs to Cheng-Gang Bian, and Wen Cao; Department of Computer Science, Faculty of Science, University of Tromsø. The software is full free for research purposes. Free to use, copy, modify and distribute. All commercial trades with this software without specific prior permission are prohibited. You don't need to register by using this software, but we appreciate your feedback or comments if you are using our software. Feedback goes to Cheng-Gang Bian (bian@stud.cs.uit.no), or Wen Cao (cao@