Examples of chemical reaction network morphisms. Circles are species and squares are reactions. Red arrows are species mappings m
and blue arrows are reaction mappings m
. Solid arrows indicate morphisms that are emulations. More examples are given in Additional file2. (A) A simple stoichiomorphism: the species in the source reactions are distinct. In general, multiple separate copies of a system will map to it via a trivial map that is a homomorphism and stoichiomorphism. (B) This is a homomorphism, but is not a stoichiomorphism. For:. (C) This is a stoichiomorphism, but is not a homomorphism or a reactant morphism. r
0 = ρ → π with but with, so and. (D) This is a homomorphism but not a stoichiomorphism. For:. (E) This stoichiomorphism is not a homomorphisms, but is a reactant morphism. r
0 = ρ → π and with and. (F) This reactant morphism is not a homomorphism but is a stoichiomorphism. E.g., for:.