7.3.3
न य्वाभ्यां पदान्ताभ्याम् पूर्वौ तु ताभ्यामैच्
Operational rule vidhi
Before a तद्धित affix with an indicatory ञ् , ण् or क् the वृद्धि is not substituted for the first vowel in a compound when it follows a word ending in य् or व् but ऐ and औ are respectively placed before the semi-vowels.
Word by word (padaccheda)
Indeclinable न avyayaLeft context य्वाभ्याम् pañcamī · dvivacanaLeft context पदान्ताभ्याम् pañcamī · dvivacanaSubstitute / term पूर्वौ prathamā · dvivacanaIndeclinable तु avyayaLeft context ताभ्याम् pañcamī · dvivacanaSubstitute / term prathamā · ekavacana
- Indeclinable An avyaya such as च "and", वा "optionally", न "not".
- Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
- Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Dotted words are technical terms, dashed ones pratyāhāras (names for classes of sounds or affixes). Hover or tap one to see its card.
Full reading
न य्वाभ्याम् पदान्ताभ्याम् पूर्वौ तु ताभ्याम्
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
Before a तद्धित affix with an indicatory ञ् , ण् or क् the वृद्धि is not substituted for the first vowel in a compound when it follows a word ending in य् or व् but ऐ and औ are respectively placed before the semi-vowels.
That is ऐ is placed before य्, and औ before व् ॥ As वैयसनम् from व्यसन; (व्यसने भवं) वैयाकरणः from व्याकरणं (व्याकरणमधीते) सौवश्वः from स्वश्वः (स्वश्वस्यापत्यं) ॥ Why after य् or व् only? Observe त्रार्थिः son of त्रर्थः ॥ Why do we say 'य् or व् final of a pada or word'? Observe याष्टीकः from यष्टिः, (यष्टिः प्रहरणमस्य) 4.4.59 याता from यति (यतेश्छात्राः or यत इमे छात्राः) ॥ The rule does not apply to दाध्यश्वि and माध्वश्वि, for no rule ordains the Vriddhi of ध्य the ध्व, and so no occasion for the prohibition of this rule arises. These are Patronyms formed by इञ् 4.1.95 from दध्यश्व and मध्वश्व (दधि प्रियोऽश्वोयस्य &c). The present rule applies to that Vriddhi also which takes place in the second member of the compound by 7.3.10 &c. As पूर्वत्रैयालिन्दः from पूर्वत्र्यलिन्द (पूर्वत्र्यलिन्दे भवः) ॥ But this prohibition does not apply where the य् or व् are not the parts of the second member, as द्व्याशीतिकः (= द्वे अशीती भूतो, भूतो भावी वा) ॥
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.