Panini’s grammar as a formal system

01A machine for words

The Ashtadhyayi, “eight chapters”, has 3,959 sutras in the received text. It begins with the fourteen Maheshvara Sutras, which tradition says came from the sound of Shiva’s damaru; they arrange the sounds of Sanskrit so that any class can be named by a two-letter code, a pratyahara, such as ac for all vowels. Then come meta-rules: how to read a sutra, which rule wins in a conflict, which apply in what order. A sutra borrows words from earlier sutras, so the whole works like a compressed program.

02Read by the moderns

Western grammar began to change once European scholars met Panini in the 19th century; the American linguist Leonard Bloomfield, in his Language of 1933, praised the Ashtadhyayi among the great achievements of the human mind. In 1967 Peter Ingerman suggested in Communications of the ACM that the notation used to define programming languages be called Panini–Backus form, because Panini had used the same kind of rewriting rules. In 2022 Rishi Rajpopat’s Cambridge thesis proposed a fresh reading of the conflict rule 1.4.2 that removes many exceptions later grammarians added.

03The living chain

Katyayana added about 4,000 vartikas, notes on where Panini needed adjustment, and Patanjali’s Mahabhashya answered them in lively dialogue; the three together are the munitraya, the three sages of grammar. Bhartrihari built a philosophy of language on them, and Bhattoji Dikshita’s Siddhanta Kaumudi of the 17th century rearranged the sutras by topic for students. Pandits still learn the Ashtadhyayi by heart in pathashalas, and Rajpopat’s claim has itself been debated by traditional grammarians, which is how a living shastra should work.

In the texts

• Ashtadhyayi
• Mahabhashya of Patanjali
• Siddhanta Kaumudi of Bhattoji Dikshita