👉 In the context of mathematical analysis and topology, "decumaria" is a term used to describe a set that is closed under certain operations. Specifically, it refers to a subset of a topological space that contains all its limit points. The concept of decumaria can be seen as a generalization of the concept of compactness in topology. It means that every open cover of a set has a finite subcover, which implies that the set is closed under certain operations. In other words