Subset models provide a new semantics for justifcation logic. The main idea of subset models is that evidence terms are interpreted as sets of possible worlds. A term then justifies a formula if that formula is true in each world of the interpretation of the term. In this paper, we introduce a belief expansion operator for subset models. We study the main properties of the resulting logic as well as the differences to a previous (symbolic) approach to belief expansion in justification logic.

翻译：子集模型为证实逻辑提供了一种新的语义。子集模型的核心思想是将证据项解释为可能世界的集合。如果一个公式在证据项解释的每个可能世界中都为真，则该项证实该公式。本文针对子集模型引入了信念扩展算子，研究了由此产生的逻辑的主要性质，以及其与先前基于符号方法的证实逻辑中信念扩展的差异。