Concept Molecules and NMR In the article Two types of coding 1, I described the challenge of getting computers to ‘understand’ the incredibly diverse range of medical diagnoses that may crop up in a text. To meet this challenge, the computer has to convert the various diagnostic formulations encountered into a consistent format that represents all the semantic details in an easily retrievable form. With concept molecules we have succeeded in doing this. We were aided here by two properties of the concept molecules method: a) the consistently composite representation of semantics, and b) a non-monotonic reasoner. At the time,