Aṣṭādhyāyī has three associated texts. The Śiva Sūtras are a brief but highly organised list of phonemes. The Dhatupatha is a lexical list of verbal roots sorted by present class. The Ganapatha is a lexical list of nominal stems grouped by common properties. Śiva Sūtras The Śiva Sūtras describe a phonemic notational system in the fourteen initial lines preceding the Aṣṭādhyāyī. The notational system introduces different clusters of phonemes that serve special roles in the morphology of Sanskrit, and are referred to throughout the text. Each cluster, called a pratyāhāra, ends with a dummy sound called an anubandha (the so-called IT index), which acts as a symbolic referent for the list. Within the main text, these clusters, referred through the anubandhas, are related to various grammatical functions. Dhātupāṭha The Dhātupāṭha is a lexicon of Sanskrit verbal roots (dhātu) of classical Sanskrit, indicating their properties and meanings. There are approximately 2300 roots in Dhātupāṭha. Of these, 522 roots are often used in classical Sanskrit. Dhātupāṭha is organised by the ten present classes of Sanskrit, i.e. the roots are grouped by the form of their stem in the present tense. The ten present classes of Sanskrit are: (root-full grade thematic presents) (root presents) (reduplicated presents) (ya thematic presents) (nu presents) (root-zero grade thematic presents) (n-infix presents) (no presents) (ni presents) (aya presents, causatives) The small number of class 8 verbs are a secondary group derived from class 5 roots, and class 10 is a special case, in that any verb can form class 10 presents, then assuming causative meaning. The roots specifically listed as belonging to class 10 are those for which any other form has fallen out of use (causative deponents, so to speak). Gaṇapāṭha The Gaṇapāṭha is a list of groups of primitive nominal stems (roots) used by the Aștâdhyāyī. Examples of groups include: Listing of verbal prefixes (upasarga). Listing of pronouns ("pronoun" is not an accurate translation but is commonly used as the list includes 'he', 'she', 'it', but also 'all' (from which the group gets its name), 'that'). Commentary After Pāṇini, the of Patañjali on the Aṣṭādhyāyī is one of the three most famous works in Sanskrit grammar. It was with Patañjali that Indian linguistic science reached its definite form. The system thus established is extremely detailed as to śikṣā (phonology, including accent) and vyākaraṇa (morphology). Syntax is scarcely touched, but nirukta (etymology) is discussed, and these etymologies