Thus suppose that a grammar were to contain the rewriting rules (12) [...] (iii) VP → V⁀NP ('examine Bill') [...] (v) VP → V⁀NP⁀Sentence ('persuade Bill that John left') [...] Object-of is defined by both (iii) and (v), so that 'Bill' is the Object-of the Verb Phrase given as examples to both (iii) and (v). - Chomsky (1969), a pag.72