Traces play a major role in several models of concurrency. They arise out of “independence structures” which are sets with a symmetric, irreflexive relation.
In this paper, independence structures are characterized as certain topological spaces. We show that these spaces are a universal construction known as “soberification”, a topological generalization of the ideal completion construction in domain theory. We also show that there is a group action connected to this construction.
Finally, generalizing the constructions in the first part of the paper, we define a new category of “labelled systems of posets”. This category includes labelled event structures as a full reflective subcategory, and has moreover a very straightforward notion of bisimulation which restricts on event structures to strong history-preserving bisimulation.