As we establish the constructions of some particular order, we define them in each case as possible sequences of constructions of lower orders. Thus, for English, the first- order word construction was defined as containing one member of 'N' or 'V' or 'A', etc., with or without certain accompanying bound classes. The second-order compound word was defined as containing two or more words plus the '— ' ' — contour. The third-order phrase constructions could be very roughly defined in terms of words and compound words: e.g. the noun phrase would usually contain 'T' 'D' 'A' 'N', where each class and each partial sequence of classes can be repeated with a member of '&' before the second occurrence; any 'D', 'A', or 'N' could be a compound word. This procedure may be repeated until we find no larger construction or domain, in any utterance no matter how long, wich we can describe as a regular combination of the last previously established domain.
- Harris (1951), Pag. 331