 In his first published book, Noam Chomsky tries to construct a formalised theory of linguistic structure and emphasises rigorous formulations and precisely constructed models. Central for Chomsky is the term grammar, a device that analyses and generates all and only the grammatical sentences of a language and rejects the ungrammatical ones. With the now famous sentence, colourless green ideas sleep furiously, he shows that even though the sentence is not included in any known corpus and is neither meaningful nor statistically probable, it is grammatically acceptable to a native speaker and concludes that grammar is autonomous and independent of meaning. He then shows that simple models such as finite state grammars or phrase structure grammars are inadequate to cope with the infinite set of grammatical sentences of a language and proposes his own formal theory of syntax called transformational generative grammar, a model that has three rule systems. Three structure rules, transformational rules and morphophonemic rules. In syntactic structures Chomsky coined the term generative to describe a finite set of rules that provide a structural description to the potentially infinite number of sentences from a finite set of elements of a particular human language. Today Chomsky's 1957 publication is considered to have started a revolution in linguistics.