Flexible Boolean semantics is a framework for analysing natural language using Boolean algebras and flexibility principles. In this article, we use flexible Boolean semantics to analyse the language of mathematics. We find that the framework cannot be used to produce desirable results for sentences in which the subject is a coordination of definite descriptions, each denoting a set, and the predicate describes a property of sets. To resolve this issue, we extend the type system and the operators from the framework to handle such sentences.