English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Forgetting is an important concept in knowledge representation and automatedreasoning with widespread applications across a number of disciplines. Astandard forgetting operator, characterized in [Lin and Reiter'94] in terms ofmodel-theoretic semantics and primarily focusing on the propositional case,opened up a new research subarea. In this paper, a new operator called weakforgetting, dual to standard forgetting, is introduced and both together areshown to offer a new more uniform perspective on forgetting operators ingeneral. Both the weak and standard forgetting operators are characterized interms of entailment and inference, rather than a model theoretic semantics.This naturally leads to a useful algorithmic perspective based on quantifierelimination and the use of Ackermman's Lemma and its fixpoint generalization.The strong formal relationship between standard forgetting and strongestnecessary conditions and weak forgetting and weakest sufficient conditions isalso characterized quite naturally through the entailment-based, inferentialperspective used. The framework used to characterize the dual forgettingoperators is also generalized to the first-order case and includes usefulalgorithms for computing first-order forgetting operators in special cases.Practical examples are also included to show the importance of both weak andstandard forgetting in modeling and representation.

Dual Forgetting Operators in the Context of Weakest Sufficient and Strongest Necessary Conditions