Existential rules form an expressive ${{\textsf{Datalog}}}$-based language to specify ontological knowledge. The presence of existential quantification in rule-heads, however, makes the main reasoning tasks undecidable. To overcome this limitation, in the last two decades, a number of classes of existential rules guaranteeing the decidability of query answering have been proposed. Unfortunately, only some of these classes fully encompass ${{\textsf{Datalog}}}$ and, often, this comes at the price of higher computational complexity. Moreover, expressive classes are typically unable to exploit tools developed for classes exhibiting lower expressiveness. To mitigate these shortcomings, this paper introduces a novel general syntactic condition that allows us to define, systematically and in a uniform way, from any decidable class $\mathcal{C}$ of existential rules, a new class called ${{\textsf{Dyadic-}\mathcal{C}}}$ enjoying the following properties: (i) it is decidable; (ii) it generalizes ${{\textsf{Datalog}}}$; (iii) it generalizes $\mathcal{C}$; (iv) it can effectively exploit any reasoner for query answering over $\mathcal{C}$; and (v) its computational complexity does not exceed the highest between the one of $\mathcal{C}$ and the one of ${{\textsf{Datalog}}}$.

存在规则形成一种基于${{\textsf{Datalog}}}$的表达语言来指定本体知识。然而，规则头中存在量化的存在使得主要推理任务无法确定。为了克服这个限制，在过去的二十年里，已经提出了许多类保证查询回答的可判定性的存在规则。不幸的是，只有其中一些类完全包含${{\textsf{Datalog}}}$，并且通常这是以更高的计算复杂性为代价的。此外，表现力类通常无法利用为表现力较低的类开发的工具。为了减轻这些缺点，本文引入了一种新的通用句法条件，它允许我们系统地、以统一的方式从存在规则的任何可判定类$\mathcal{C}$定义一个名为${{\textsf的新类{Dyadic-}\mathcal{C}}}$具有以下属性： ( i ) 它是可判定的；( ii ) 它概括了${{\textsf{Datalog}}}$；( iii ) 它概括了$\mathcal{C}$；( iv ) 它可以有效地利用任何推理器来回答$\mathcal{C}$上的查询；( v )其计算复杂度不超过$\mathcal{C}$与${{\textsf{Datalog}}}$之间最高的一个。