ओतो गार्ग्यस्य

Operational rule vidhi

Non-लघूच्चारण-यकार present at end of a पद and situated after the letter ओ gets removed when it is followed by a letter from अश् प्रत्याहार in the context of संहिता.

Word by word (padaccheda)

Left context ओतः pañcamī · ekavacanaTarget गार्ग्यस्य ṣaṣṭhī · ekavacana

Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).

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

ओतः गार्ग्यस्य

Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.

Commentary

य् preceded by ओ is elided before an अश् letter (vowels and soft-consonants) according the opinion of गार्ग्य ।
There can be no व् preceded by ओ, so only य् is taken in explaining the sutra. Thus भो अत्र, भगो अत्र, भो इदम्, भगो इदम् ॥

The making of it a separate sutra, is for the sake of indicating that this is a necessary (nitya) rule and not a vibhasha rule. The name of Gargya is used simply honoris causa (pujartha). The elision of laghu-prayatna य्, which 8.3.19 would have otherwise caused, is hereby prohibited. So that
laghu pratyatnatara य् does come also. As भो अत्र or भोयत्र, भगो अत्र or भगोयत्र, अघो अत्र and अघोयत्र ॥

According to others every kind of य् (whether heavy or light) is to be elided: and भोयत्र is not valid in their opinion.

Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.