As described above, we arbitrarily align the SynGraph equality property to the route equivalence level that captures the single reactions' reactants and products. This decision aligns with the formal treatment of retrosynthesis provided by Corey and Hoffman and ensures the best compatibility across CASP tools and NOC databases. The SynGraph (a value object) is thus a label for synthetic routes (entities). The other layers of route equivalence find their place in the data model but do not contribute to the route "label." We build the route identity logic on the equality of the dictionaries of sets that constitute SynGraph. Two dictionaries are identical when they have the same key-value pairs. Since both keys and values are Molecule or ChemicalEquation instances (value objects), the SynGraph equivalence conveniently relies on standard python compassion functions.