Abstract This article is a preliminary presentation of conjunctive paraconsistency , the claim that there might be non-explosive true contradictions, but contradictory propositions cannot considered separately true. In case ‘p and not p’, conjuncts must held untrue, Simplification fails. The approach dual to non-adjunctive conceptions inconsistency, informed by idea cases in which proposition i...

In the optimization of queries in an object-oriented database system (OODB), a natural rst step is to use the typing constraints imposed by the schema to transform a query into an equivalent one that logically accesses a minimal set of objects. We study a class of queries for OODB's called conjunctive queries. Variables in a conjunctive query range over heterogeneous sets of objects. Consequent...

Aquifers are ubiquitous, and their water is easy to obtain with low extraction costs. On many occasions, these characteristics lead overexploitation due important level declines, reduction of river base flows, enhanced seawater intrusion, wetland affection. The forecasted increase in demands global warming will impact the future availability resources. Conjunctive use surface subsurface waters ...

We study conjunctive query answering in the description logic EL, the core of the designated OWL2-EL profile of OWL2. In particular, we present an approach that allows the use of conventional relational database technology for conjunctive query answering in EL. This approach is inspired by the OWL support in Oracle Database 11g, semantic technologies.

The most heavily used methods to answer conjunctive queries on binary relations (such as the one associating keywords with web pages) are based on inverted lists stored in sorted arrays and use variants of binary search. We show that a succinct representation of the binary relation permits much better results, while using space within a lower order term of the optimal. We apply our results not ...

We study the containment, satisfiability, and validity problems for conjunctive queries over trees with respect to a schema. We show that conjunctive query containment and validity are 2EXPTIMEcomplete w.r.t. a schema (DTD or Relax NG). Furthermore, we show that satisfiability for conjunctive queries w.r.t. a schema can be decided in NP. The problem is NP-hard already for queries using only one...