Panini’s grammar is the earliest scientific grammar in the world, the earliest extant grammar of any language, and one of the greatest ever written. … - Panini

Ashtadhyayi Sanskrit treatise on grammar was written in the 6th to 5th century BCE by the Indian grammarian Panini. This work set the linguistic standards for Classical Sanskrit. It sums up in 4,000 sutras the science of phonetics and grammar that had evolved in the Vedic religion. Panini divided his work into eight chapters, each of which is further divided into quarter chapters, beyond defining the morphology and syntax of Sanskrit language.

A treatise called Astadhyayi (or Astaka) is Panini's major work. It consists of eight chapters, each subdivided into quarter chapters. In this work Panini distinguishes between the language of sacred texts and the usual language of communication. Panini gives formal production rules and definitions to describe Sanskrit grammar. Starting with about 1700 basic elements like nouns, verbs, vowels, consonants he put them into classes. The construction of sentences, compound nouns etc., is explained as ordered rules operating on underlying structures in a manner similar to modern theory. In many ways Panini's constructions are similar to the way that a mathematical function is defined today.

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.