Define mass-action ME models within CRN

Determine a mathematically precise definition of mass-action mathematical epidemiology (ME) models as a subclass of chemical reaction networks (CRNs), potentially restricted to monomolecular transfers and the bimolecular infection reactions S + E -> 2E and S + I -> I + E as encountered in SEIR-type systems, so that ME models are explicitly characterized within CRN theory.

Background

The paper notes that a formal definition of ME models is currently lacking and that certain CRN features (e.g., weak reversibility, zero deficiency) may be incompatible with ME depending on how ME is defined. To bridge the disciplines, the authors propose grounding ME models as a specific subclass of CRNs.

This problem seeks a clear, rigorous delineation of ME models within CRN, specifying allowable reaction types and structures to unify analysis and enable cross-application of CRN tools to ME.