A Lower Bound on Conservative Elementary Object Systems Coverability

Abstract

Elementary Object Systems (EOS) are a form of Petri Net (PN) where tokens carry internal PN. This model has been recently proposed for analysis of robustness of Multi Agent Systems. While EOS reachability is known to be undecidable, the decidability of coverability of its conservative fragment (where the type of internal PN cannot be completely deleted and, thus, is conserved) was proved a decade ago, no study charted its complexity. Here, we take a first step in this direction, by showing how to encode $\hat{I}½$PNs, a well studied form of PN enriched with data, into conservative EOS (cEOS). This yields a non-Primitive Recursive, $F_{\omega 2}$ lower-bound on cEOS coverability.

8 pages, 1 figure, part of a submission to a journal