Enhancing the Expressive Power of the U-Datalog Language

Title: Enhancing the Expressive Power of the U-Datalog Language

Research Question: How can the expressive power of the U-Datalog language be enhanced to handle negative information more effectively?

Methodology: The researchers proposed a semantics, based on stratification, for handling negated atoms in U-Datalog programs. They aimed to define a compositional semantics that would allow for the consistent combination of negative and positive information.

Results: The researchers identified several problems in defining a compositional semantics for U-Datalog with negated atoms. They found that the existing semantics of U-Datalog is not suitable for handling negation, as it does not provide a mechanism to explicitly deal with negative information. They also discovered that the language's current approach to update execution can lead to inconsistencies, as it does not handle the insertion and deletion of the same fact.

Implications: The research highlights the limitations of the U-Datalog language in handling negative information. The identified problems suggest that modifications to the language's semantics and operational semantics are necessary to enhance its expressive power. The research also contributes to the ongoing efforts in developing more expressive and flexible logical update languages.

Link to Article: https://arxiv.org/abs/0404003v1 Authors: arXiv ID: 0404003v1