Diagrams, or comparable geometric and physical models, can be constructed so as to represent all the substitutions or equivalences, conditioned by particular concurrent environments, recognized via chapters 16,18. However, such diagrams would in most cases be extremely complicated, and the advantage of easy inspection would be lost. For particular constructions or parts of utterances the diagram may provide a convenient summary of the relations of chapters 16 or 18.
- Harris (1951), a pag.352