Sanskrit grammatical tradition (vyākaraṇa, one of the six Vedanga disciplines) began in late Vedic India and culminated in the Aṣṭādhyāyī of Pāṇini, which consists of 3990 sutras (ca. 5th century BCE). About a century after Pāṇini (around 400 BCE), Kātyāyana composed vārtikas (explanations) on the Pāṇinian sũtras. Patañjali, who lived three centuries after Pāṇini, wrote the Mahābhāṣya, the "Great Commentary" on the Aṣṭādhyāyī and Vārtikas.