论文标题
存在规则的有限范围：迈向一般标准，以确定但高度表达的查询
Finite-Cliquewidth Sets of Existential Rules: Toward a General Criterion for Decidable yet Highly Expressive Querying
论文作者
论文摘要
为了追求基于本体本体的查询的通用标准，我们介绍了存在规则的“有限 - 局限性集合”（FCS），这是一种模型定义的规则集类别，灵感来自图形理论的cliquewidth措施。通过一个通用参数，我们表明FCS确保对相当一类的查询类（称为“ Damsoqs”）的必要性包含结合性查询（CQS）。 FCS类适当地概括了有限膨胀集（FES）的类别，并且最多可以介绍2个arity的签名，即有界树的类别（BTS）。对于较高的ARIT，BTS仅由FC间接地归入FC，以归因。尽管FC的一般性，但我们提供了一个规则集，该规则集（根据一阶 - 剥离性）属于FCS之外，从而证明了FCS的无与伦比和有限合并集（FUS）的无效性。尽管如此，我们表明，如果我们将自己限制在最多2的单头规则上，则最多只能使用2个签名，则FCS属于FUS。
In our pursuit of generic criteria for decidable ontology-based querying, we introduce 'finite-cliquewidth sets' (FCS) of existential rules, a model-theoretically defined class of rule sets, inspired by the cliquewidth measure from graph theory. By a generic argument, we show that FCS ensures decidability of entailment for a sizable class of queries (dubbed 'DaMSOQs') subsuming conjunctive queries (CQs). The FCS class properly generalizes the class of finite-expansion sets (FES), and for signatures of arity at most 2, the class of bounded-treewidth sets (BTS). For higher arities, BTS is only indirectly subsumed by FCS by means of reification. Despite the generality of FCS, we provide a rule set with decidable CQ entailment (by virtue of first-order-rewritability) that falls outside FCS, thus demonstrating the incomparability of FCS and the class of finite-unification sets (FUS). In spite of this, we show that if we restrict ourselves to single-headed rule sets over signatures of arity at most 2, then FCS subsumes FUS.
