6.3.111
ढ्रलोपे पूर्वस्य दीर्घोऽणः
Operational rule vidhi
When a ढकार is deleted due to a ढकार that follows it, or when a रेफ is deleted due to a रेफ that follows the अण् letter occurring before the deleted ढकार/रेफ becomes दीर्घ.
Word by word (padaccheda)
Right context ढ्रलोपे saptamī · ekavacanaTarget पूर्वस्य ṣaṣṭhī · ekavacanaSubstitute / term prathamā · ekavacanaTarget ṣaṣṭhī · ekavacana
- Right context Saptamī (7th case): "when X follows", the operation applies to what precedes (1.1.66 तस्मिन्निति निर्दिष्टे पूर्वस्य). Also a condition or domain ("in the sense of").
- Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).
- 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
ढ्रलोपे पूर्वस्य
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
पूर्वस्य → / ढ्रलोपे
Replace pūrvasya aṇaḥ with dīrghaḥ when ḍhralope follows. Inherited words (anuvṛtti) may add further conditions.
Commentary
When ढ् or र् is elided for the preceding अ , इ and उ a corresponding long vowel is substituted.
Thus लीढम्, मीढम्, उपगूढम् ॥ रलोपे-निर्-रक्तम् = नीरक्तम्, अग्निर् रथः = अग्नीरथः, इन्दू रथः, पुना रक्तम् वासः, प्राता राजक्रयः ॥ For the elision of ढ see 8.3.13, and for the elision of र् see 8.3.14. But आवृढम्, the ऋ is not lengthened because it is not included in the pratyahara अण् which is formed with the ण of अ इ उ ण् ॥
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.