🤖 AI Summary
Concurrent models—including higher-dimensional automata, Petri nets, and vector addition systems—suffer from semantic fragmentation due to disparate formal foundations.
Method: We introduce *presheaf automata*, a categorical framework built on the category of presheaves over paths, unifying their semantics. Automaton semantics are defined via presheaves; formal languages are characterized by path and trace objects; and simulation and bisimulation are generalized using open maps.
Contributions: (1) The first systematic application of presheaf methods to automata theory; (2) A precise embedding of finitely presentable presheaf automata into arbitrary (not necessarily safe) Petri nets, overcoming prior restrictions; (3) A comprehensive theoretical framework encompassing language equivalence, behavioral equivalences (e.g., simulation, bisimulation), and expressive power—establishing a unified semantic foundation for concurrent systems.
📝 Abstract
We introduce presheaf automata as a generalisation of different variants of higher-dimensional automata and other automata-like formalisms, including Petri nets and vector addition systems. We develop the foundations of a language theory for them based on notions of paths and track objects. We also define open maps for presheaf automata, extending the standard notions of simulation and bisimulation for transition systems. Apart from these conceptual contributions, we show that certain finite-type presheaf automata subsume all Petri nets, generalising a previous result by van Glabbeek, which applies to higher-dimensional automata and safe Petri nets.