Fig. 1From: Learning chemistry: exploring the suitability of machine learning for the task of structure-based chemical ontology classificationThe figure illustrates the many branching and partially overlapping ancestor classes subsuming the molecule L-alanine (CHEBI:16977). Each of the illustrated mid-level classes similarly contains an overlapping range of molecular entity leaf members. For this reason, the ChEBI ‘chemical entity’ ontology can be described as diamond-shaped. Blue arrows indicate subsumption relationships and the black arrow indicates a parthood relationshipBack to article page