Conceptual structures: information processing in mind and machine
Conceptual structures: information processing in mind and machine
Negation in rule-based database languages: a survey
Selected papers of the workshop on Deductive database theory
A database needs two kinds of negation
MFDBS 91 Proceedings of the 3rd symposium on Mathematical fundamentals of database and knowledge base systems
Conjunctive-query containment and constraint satisfaction
Journal of Computer and System Sciences - Special issue on the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Knowledge Retrieval and the World Wide Web
IEEE Intelligent Systems
Information Integration Using Logical Views
ICDT '97 Proceedings of the 6th International Conference on Database Theory
Containment of Conjunctive Queries with Safe Negation
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Basic Conceptual Structures Theory
ICCS '94 Proceedings of the Second International Conference on Conceptual Structures: Current Practices
A Direct Proof Procedure for Definite Conceptual Graph Programs
ICCS '95 Proceedings of the Third International Conference on Conceptual Structures: Applications, Implementation and Theory
Modelling and Simulating Human Behaviours with Conceptual Graphs
ICCS '97 Proceedings of the Fifth International Conference on Conceptual Structures: Fulfilling Peirce's Dream
Knowledge Representation and Reasonings Based on Graph Homomorphism
ICCS '00 Proceedings of the Linguistic on Conceptual Structures: Logical Linguistic, and Computational Issues
A Conceptual Graph Model for W3C Resource Description Framework
ICCS '00 Proceedings of the Linguistic on Conceptual Structures: Logical Linguistic, and Computational Issues
Foundations of semantic web databases
PODS '04 Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
A content-search information retrieval process based on conceptual graphs
Knowledge and Information Systems
Extensions of simple conceptual graphs: the complexity of rules and constraints
Journal of Artificial Intelligence Research
RDF entailment as a graph homomorphism
ISWC'05 Proceedings of the 4th international conference on The Semantic Web
A Comparison of Different Conceptual Structures Projection Algorithms
ICCS '07 Proceedings of the 15th international conference on Conceptual Structures: Knowledge Architectures for Smart Applications
An Algorithmic Study of Deduction in Simple Conceptual Graphs with Classical Negation
ICCS '08 Proceedings of the 16th international conference on Conceptual Structures: Knowledge Visualization and Reasoning
The Advent of Formal Diagrammatic Reasoning Systems
ICFCA '09 Proceedings of the 7th International Conference on Formal Concept Analysis
Default conceptual graph rules, atomic negation and Tic-Tac-Toe
ICCS'10 Proceedings of the 18th international conference on Conceptual structures: from information to intelligence
Deduction in existential conjunctive first-order logic: an algorithm and experiments
AIMSA'10 Proceedings of the 14th international conference on Artificial intelligence: methodology, systems, and applications
Understanding permissions through graphical norms
DALT'10 Proceedings of the 8th international conference on Declarative agent languages and technologies VIII
Some algorithmic improvements for the containment problem of conjunctive queries with negation
ICDT'07 Proceedings of the 11th international conference on Database Theory
Graphical norms via conceptual graphs
Knowledge-Based Systems
Simple conceptual graphs with atomic negation and difference
ICCS'06 Proceedings of the 14th international conference on Conceptual Structures: inspiration and Application
Knowledge representation and reasoning for qualitative spatial change
Knowledge-Based Systems
On the complexity of entailment in existential conjunctive first-order logic with atomic negation
Information and Computation
Efficient processing of twig query with compound predicates in fuzzy XML
Fuzzy Sets and Systems
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We consider basic conceptual graphs, namely simple conceptual graphs (SGs), which are equivalent to the existential conjunctive positive fragment of first-order logic. The fundamental problem, deduction, is performed by a graph homomorphism called projection. The existence of a projection from a SG Q to a SG G means that the knowledge represented by Q is deducible from the knowledge represented by G. In this framework, a knowledge base is composed of SGs representing facts and a query is itself a SG. We focus on the issue of querying SGs, which highlights another fundamental problem, namely query answering. Each projection from a query to a fact defines an answer to the query, with an answer being itself a SG. The query answering problem asks for all answers to a query. This paper introduces atomic negation into this framework. Several understandings of negation are explored, which are all of interest in real world applications. In particular, we focus on situations where, in the context of incomplete knowledge, classical negation is not satisfactory because deduction can be proven but there is no answer to the query. We show that intuitionistic deduction captures the notion of an answer and can be solved by projection checking. Algorithms are provided for all studied problems. They are all based on projection. They can thus be combined to deal with several kinds of negation simultaneously. Relationships with problems on conjunctive queries in databases are recalled and extended. Finally, we point out that this discussion can be put in the context of semantic web databases.