The atom mapping tool RXNMapper developed by Schwaller et al. utilised NLP to infer reaction structures. A neural network (transformer) was trained on a set of mapped reactions and proved to be capable of completing the mapping tasks quicker and with confidence scores. Nugmanov et al. developed a rule-based reaction balancing method and this has been integrated into a reaction informatics software, namely, CGRtools. However, this could only add small molecules such as water, and the author claimed the balancing was imperfect. Thus, till now inferring complete reaction structure from incomplete reaction datasets remains a challenge.