String Diagrams for Physical Duoidal Categories
arXiv:2406.19816
Abstract
We introduce string diagrams for physical duoidal categories (normal -symmetric duoidal categories): they consist of string diagrams with wires forming a zigzag-free partial order and order-preserving nodes whose inputs and outputs form intervals.
26 pages, 11 figures. The author thanks Nayan Rajesh for pointing out a mistake on a previous version of Definition 8.4