Extending Acyclicity Notions for Existential Rules

Quad-System dChase size w.r.t Data Complexity of Combined Complexity Fragment input quad-system CCQ entailment of CCQ entailment Unrestricted Quad-Systems Infinite

- In-vivo: Students enrolled in a course use the software tutor in the class room, typically under tightly controlled conditions and under the supervision of the

The chase procedure (or simply chase) is considered as one of the most fundamental algorithmic tools in databases — it accepts as input a database D and a set Σ of con- straints and,

The following example shows a case where a given database does not satisfy a set of tuple generating dependencies (TGDs) and the application of the chase algorithm produces a

We study chase termination by exploiting in a novel way a graph structure, namely the derivation tree, which was originally introduced to solve the ontology-mediated (conjunctive)

We study chase termination by exploiting in a novel way a graph structure, namely the derivation tree, which was originally introduced to solve the ontology-mediated (conjunctive)

The classes of rule sets whose chase terminates on all paths (all possible derivation sequences of chase steps) independent of given databases (thus all instances) is denoted by CT ∀∀

For this reason, we develop new acyclicity conditions [1] that guarantee re- stricted chase termination of a TBox over any ABox, by extending known acyclicity notions to the