The choice of the identity attributes of Molecule and ChemicalEquation univocally echoes the identity attribute of SynGraph and defines the equality operations between its instances. For example, the same SynGraph maps two distinct routes having identical reactants and products for each reaction step, irrespective of the reagents, physical conditions, operative procedures, etc. This data model layer maps the business logic's first layer and is open to extensions to deeper layers by including other properties of the Molecule or ChemicalEquation. Additional types of nodes and relationships can extend the data model to enable different equivalence assessments between SynGraph instances that include other aspects of the chemical reaction.