Travelers in Grammar will remain always a project. It does not mean the books and courses never end, or remain unfinished.
What is grammar?
“…a language is an infinite set of sentences which are triplets of phonetic, syntactic, and semantic properties generated by a finite abstract project, or grammar, which consists of sets of partially independent elements called rules and a lexicon or dictionary. Such grammars are represented in human neural systems and provide implicit knowledge of the language they define. A grammar is thus in certain ways analogous to a computer program in that it is a formal system partially determining the behaviour of a physical system (…)”
Nature and information
In the 20th century, neurophysiology began applying the phrase information processing to human bodily structures. Fair and square, if we see a cat or a dog, our eyes give us information on the animal being around. We are not just under an impression we see it, or experience premonition on life on Earth. At the same time, nobody would go on a lookout for cats or dogs, to tell the weather.
Program and feedback
It is natural grammar to have natural language information. This information gets operated by human nervous systems, and this in basically two modes: closed-loop or open-loop. The open-loop processes go their course as the instruction requires. They are compared to programs. Closed-loop processes are feedback.
Nature delimits on programs. Live nervous systems need to sustain in variable ecosystems. Excess program would thwart the ability to react and adapt. All biological programs depend on feedback, including the DNA for active protein.
In everyday language, feedback is associated with opinion, or physical control. Obviously, live nervous systems are not opinionated tyrannies. Feedback is a biological capability for closed-loop interaction. It becomes generated as necessary, among neural and other structures.
For the proportion on program and feedback in language, we can compare spoonerisms. The slips are segmental, and this is about the scope the nervous system allows pre-determined routines for language.
A program is predetermined from beginning to end. Natural language is infinite. There is no way to calculate all possible forms or structures, and there is no genetic program to produce literature. To manage own language skill, we need own brain logic. This logic can produce finite sets as projects, yet never as programs. Natural grammar cannot be analogous to a computer program.