EQ model. In the schematic part, E stands for entity, Q for quality, and R for relational quality. Schema a) accounts for a simple (unary or non-relational) quality, while b) refers to relational qualities. The examples c) and d) correspond to those from the text. Example e) in parallel with d) is forestalling the problem of inter-modeler consistency from the Methods section. 'conc.' in d) and e) abbreviates concentration of.