Pāṇini is known for his Sanskrit grammar, particularly for his formulation of the 3,959 rules of Sanskrit morphology, syntax and semantics in the grammar known as Ashtadhyayi (अष्टाध्यायी Aṣṭādhyāyī, meaning "eight chapters"), the foundational text of the grammatical branch of the Vedanga, the auxiliary scholarly disciplines of Vedic religion [Hinduism] . Pāṇini's comprehensive and scientific theory of grammar is conventionally taken to mark the end of the period of Vedic Sanskrit, introducing the period of Classical Sanskrit.