Prastāra–Naṣṭa Procedures and Enumeration of Chandas
Laghu–Guru Computation
लगसंख्या वृत्तसंख्या चाद्याङ्गुलमथोर्ध्वतः / संख्यैव द्विगुणैकोनाच्छन्दः सारो ऽयमीरितः
lagasaṃkhyā vṛttasaṃkhyā cādyāṅgulamathordhvataḥ / saṃkhyaiva dviguṇaikonācchandaḥ sāro 'yamīritaḥ
Số lượng laga (nhóm nhịp) và số lượng vṛtta (thể thơ), bắt đầu từ đơn vị đo đầu tiên rồi lần lượt đi lên—khi lấy con số ấy nhân đôi rồi trừ một—được tuyên nói là quy tắc cốt yếu để định chandas (luật thi vận).
Lord Vishnu (in instruction to Garuda/Vinata-putra, within the Brahma Kanda’s didactic sections)
Concept: Prosodic enumeration: counts of lagas and vṛttas derived by a doubling-minus-one rule across measures.
Vedantic Theme: Śabda-brahma orientation: disciplined sound/measure as a support for sacred knowledge; order in speech mirrors order in mind.
Application: For metrical cataloging: starting from the first unit and moving upward, compute total patterns by ‘2n−1’ (doubling then subtracting one) as the stated chandas-sāra rule; apply to generate/verify meter counts.
Primary Rasa: shanta
Secondary Rasa: adbhuta
Related Themes: Garuda Purana 1.212 surrounding verses: prastāra/uddiṣṭa/naṣṭa-like computational rules for chandas
This verse treats chandas as a technical discipline: correct metrical knowledge preserves accurate recitation and transmission of Purāṇic teaching.
It gives a compact computational rule: take the relevant count (of metrical groupings/meters), double it, and subtract one—presented as the ‘essence’ for chandas determination in this context.
Use it as a mnemonic when studying Sanskrit meters: disciplined counting and rule-based verification help keep chanting and textual study precise.