Trademark Office (USPTO) database, and the commercial platform Reaxys ® . These databases catalogue millions of chemical reactions, facilitating data-driven methodologies in synthesis planning. Specifically, Reaxys ® , with its collection of over 55 million manually curated reactions, has become a pivotal resource for implementing deep learning models in retrosynthesis. Efficient synthesis planning for novel compounds, by its very nature, requires reasoning by analogy. This can be greatly facilitated by a representation of reactions that provides transformation rules applicable to novel compounds and novel combinations of reactants.