In the fifteenth century Rāmachandra, in his Prakriyā-kaumudī, or "Moonlight of Method," endeavoured to make Pāṇini's grammar easier by a more practi… - Panini

Roman alphabet:
siṃho vyākaraṇasya kartur aharat prāṇān priyān pāṇineḥ

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.

The issue of theism vis-à-vis atheism, in the ordinary senses of the English words, played an important role in Indian thought. The ancient Indian tradition, however, classified the classical systems (darshanas) into orthodox (astika) and unorthodox (nastika). Astika does not mean “theistic,” nor does nastika mean “atheistic.” Panini, a 5th-century-BCE grammarian, stated that the former is one who believes in a transcendent world (asti paralokah) and the latter is one who does not believe in it (nasti paralokah).