2026-08-21T18:02:51Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:27431 2026-08-21T14:42:39Z ddc:004 open_access

Hypergraphs for Compact Closed Categories Di Giorgio, Alessandro Reader, Callum rewriting compact closed categories string diagrams In recent years a succession of papers have taken to representing string diagrams as hypergraphs, the advantage of which is that the structural equations of diagrams come for free from the hypergraph structure. This improves implementability and reduces the number of rewrites necessary for reasoning. Notably, however, string diagrams for compact closed categories have escaped this treatment. In this paper we introduce a combinatorial interpretation of compact closed string diagrams, via the Int construction on hypergraphs for traced string diagrams. Using this interpretation, we characterise string diagram rewriting as a suitable adaptation of double-pushout rewriting. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Alessandro Di Giorgio and Callum Reader 2026 Is Part Of LIPIcs, Volume 386, 51st International Symposium on Mathematical Foundations of Computer Science (MFCS 2026) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.MFCS.2026.50 urn:nbn:de:0030-drops-274318 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2026.50 eng https://creativecommons.org/licenses/by/4.0/legalcode