Datalog extension for nested relations

An Extension of an Algebra for Nested Relations

DATALOG with Nested Rules

This paper presents an extension of disjunctive datalog (Datalog∨) by nested rules. Nested rules are (disjunctive) rules where elements of the head may be also rules. Nested rules increase the knowledge representation power of Datalog∨ both from a theoretical and from a practical viewpoint. A number of examples show that nested rules allow to naturally model several real world situations that c...

An Extension of Datalog for Graph Queries

Supporting aggregates in recursive logic rules is a crucial long-standing problem for Datalog. To solve this problem, we propose Datalog that supports queries and reasoning on the number of distinct occurrences satisfying given goals, or conjunction of goals, in rules. By using a generalized notion of multiplicity called frequency, we show that graph queries can be easily expressed in Datalog ....

Sedatalog: A Set Extension of Datalog

In this paper we propose an extension, SEDatalog, of Datalog so that sets can be constructed naturally in logic programming. In SEDatalog, sets can be defined by statements so it has a strong capability in creating sets, and we can use sets in SEDatalog exactly in the way we use them in mathematics or other fields. With the notion of ”order” introduced in this paper, confusions among set constr...

Finitely Representable Nested Relations

Advanced temporal and spatial applications require both the representation of complex objects and the ability to nitely represent innnite relations. Representing such data requires combining the constraint relational model (allowing nite representation of innnite information) and either the nested relational or the object-oriented model (allowing representation of complex objects). In this pape...