Standpoint EL is a multi-modal extension of the popular description logic EL that allows for the integrated representation of domain knowledge relative to diverse standpoints or perspectives. Advantageously, its satisfiability problem has recently been shown to be in PTime, making it a promising framework for large-scale knowledge integration. In this paper, we show that we can further push the expressivity of this formalism, arriving at an extended logic, called Standpoint EL+, which allows for axiom negation, role chain axioms, self-loops, and other features, while maintaining tractability. This is achieved by designing a satisfiability-checking deduction calculus, which at the same time addresses the need for practical algorithms. We demonstrate the feasibility of our calculus by presenting a prototypical Datalog implementation of its deduction rules.

翻译：Standpoint EL是流行描述逻辑EL的多模态扩展，支持整合表示相对于不同立场或视角的领域知识。其优势在于，可满足性问题最近被证明属于PTime复杂度类，使其成为大规模知识集成的有前景框架。本文表明，我们可进一步扩展该形式体系的表达能力，得到名为Standpoint EL+的扩展逻辑——该逻辑在保持可处理性的同时，支持公理否定、角色链公理、自环及其他特性。这一突破通过设计可满足性检验的演绎演算实现，同时满足了实用算法的需求。我们通过展示演绎规则的Datalog原型实现，验证了该演算的可行性。