Introduction to Guarded Horn Clauses

Transformation of Guarded Horn Clauses for Model Building

The guarded fragment of rst order logic has been de ned in [ABN96]. It is interesting due to the fact that it is decidable and several modal logics can be translated into it. Guarded clauses, de ned by de Nivelle in [Niv98], result from transformation of guarded formulas into clause form. In [Niv98], it is shown that the class of guarded clause sets is decidable by saturation under ordered reso...

Guarded Horn Clauses

This thesis introduces the programming language Guarded Horn Clauses which is abbreviated to GHC. Guarded Horn Clauses was born from the examination of existing logic programming languages and logic programming in general, with special attention paid to parallelism. The main feature of GHC is its extreme simplicity compared with the other parallel programming languages. GHC is a restriction of ...

Guarded Horn Clauses: A Parallel Logic Programming Language with the Concept of a Guard

Guarded Horn Clauses Application and Implementation

The programming language Guarded Horn Clauses is described. Different programming techniques suitable for the language are explained. How fast can a GHC program execute, if run on an ideal parallel computer with a sufficient number of processors? A simulator that is intended to help answering that question is presented. A parallel sorting algorithm is presented and tested on the simulator. A si...

ProbLog Technology for Inference in a Probabilistic First Order Logic

We introduce First Order ProbLog, an extension of first order logic with soft constraints where formulas are guarded by probabilistic facts. The paper defines a semantics for FOProbLog, develops a translation into ProbLog, a system that allows a user to compute the probability of a query in a similar setting restricted to Horn clauses, and reports on initial experience with inference.