Ashtadhyayi distinguishes between usage in the spoken language and usage that is proper to the language of the sacred texts. The Ashtadhyayi is generative as well as descriptive. With its complex use of metarules, transformations, and recursions, the grammar in Ashtadhyayi has been likened to the Turing machine, an idealized mathematical model that reduces the logical structure of any computing device to its essentials.

Encyclopedia Britannica in: "Panini Indian grammarian".