Fig. 1

Structure of the pharmacophore network. Each circle is a vertex containing a pharmacophore. Only the pharmacophoric features are displayed to simplify the example and the separators “|” are removed for ease of readability. Molecules having the pharmacophore are indicated in the colored rectangles using set notation. The notation \(\{{M}_{3},\dots ,{M}_{6}\}\) indicates that the set is composed of molecules \({M}_{3},{M}_{4},{M}_{5},and\,{M}_{6}\). The molecules associated to a pharmacophore is determined by the colored area its vertex is in. Edges displays the inclusion relation between pharmacophores. The vertex containing AN is connected to the vertices containing ARN and ADN because AN is a subgraph of ARN and ADN. Since AN is associated with molecules \({M}_{1}\) and \({M}_{2}\), ARN and ADN must be associated to a subset of \({\{M}_{1},{M}_{2}\}\). In this example, these pharmacophores are associated to the molecule \({M}_{2}\).