the phrasal equations, and some of the poetic metres. While there are similarities, state Jamison and Brereton, there are also differences between Vedic Sanskrit, the Old Avestan, and the Mycenaean Greek literature. For example, unlike the Sanskrit similes in the Ṛg-veda, the Old Avestan Gathas lack simile entirely, and it is rare in the later version of the language. The Homerian Greek, like Ṛg-vedic Sanskrit, deploys simile extensively, but they are structurally very different. Classical Sanskrit The early Vedic form of the Sanskrit language was far less homogenous compared to the Classical Sanskrit as defined by grammarians by about the mid-1st millennium BCE. According to Richard Gombrich—an Indologist and a scholar of Sanskrit, Pāli and Buddhist Studies—the archaic Vedic Sanskrit found in the Rigveda had already evolved in the Vedic period, as evidenced in the later Vedic literature. Gombrich posits that the language in the early Upanishads of Hinduism and the late Vedic literature approaches Classical Sanskrit, while the archaic Vedic Sanskrit had by the Buddha's time become unintelligible to all except ancient Indian sages. The formalization of the Sanskrit language is credited to , along with Patanjali's and Katyayana's commentary that preceded Patañjali's work. Panini composed ('Eight-Chapter Grammar'). The century in which he lived is unclear and debated, but his work is generally accepted to be from sometime between the 6th and 4th centuries BCE. The was not the first description of Sanskrit grammar, but it is the earliest that has survived in full, and the culmination of a long grammatical tradition that Fortson says, is "one of the intellectual wonders of the ancient world." Pāṇini cites ten scholars on the phonological and grammatical aspects of the Sanskrit language before him, as well as the variants in the usage of Sanskrit in different regions of India. The ten Vedic scholars he quotes are Āpiśali, Kaśyapa, Gārgya, Gālava, Cakravarmaṇa, Bhāradvāja, Śākaṭāyana, Śākalya, Senaka and Sphoṭāyana. The of Panini became the foundation of Vyākaraṇa, a Vedānga. In the , language is observed in a manner that has no parallel among Greek or Latin grammarians. Pāṇini's grammar, according to Renou and Filliozat, is a classic that defines the linguistic expression and sets the standard for the Sanskrit language. Pāṇini made use of a technical metalanguage consisting of a syntax, morphology and lexicon. This metalanguage is organised according to a series of meta-rules, some of which are explicitly stated while others can be