Directed acyclic open hypergraphs are a data structure useful to represent symmetric monoidal categories.
- The explicit data structure is described in Cartographer, a Tool for String Diagrammatic Reasoning (Sobocinski, Wilson, Zanasi).
- A practical justification for the use of open hypergraphs is given in Rewriting Modulo Symmetric Monoidal Structure (Bonchi, Gadducci, Kissinger, Sobocinski, Zanasi).
- Perhaps related, a completely different approach is described in Hypergraph construction and its application to the static analysis of concurrent systems (König).