(2) (i) I called the man who wrote the book that you told me about up [...] The phrases 'A' and 'B' form a nested construction if 'A' falls totally within 'B', with some nonnull element to its left within 'B' and some nonnull element to its right within 'B'. Thus the phrase "the man who wrote the book that you told me about" is nested in the phrase "called the man who wrote the book that you told me about up", in (2i).
- Chomsky (1969), Pag. 12