Lexical items are more or less the accidental results of transformations which substantify, or 'incorporate', the trees referred to in (i), or constituent parts ('subtrees') of them, into entities which, for reasons of practical economy are labelled with single lexical items.

the length of a book

… from a vantage point of security, the lawyer is taught to ask the question from the vantage point of one lying halfdead by the side of the road.

Lab tests would later reveal that the plant material was actually loose-leaf tea.