उत्तरमृगपूर्वाच्च सक्थ्नः

Operational rule vidhi

The affix टच् comes after सक्थि when preceded by 1. उत्तर 2. मृग 3. पूर्व in a तत्-पुरुष समास as well as when a thing is compared with it.

Word by word (padaccheda)

Left context उत्तर- मृग- पूर्वात् pañcamī · ekavacanaIndeclinable च avyayaLeft context सक्थ्नः pañcamī · ekavacana

Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
Indeclinable An avyaya such as च "and", वा "optionally", न "not".

Dotted words are technical terms. Hover or tap one to see its card.

Full reading

उत्तर-मृग-पूर्वात् च सक्थ्नः

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

Commentary

The affix टच् comes after सक्थि when preceded by 1. उत्तर 2. मृग 3. पूर्व in a तत्-पुरुष समास as well as when a thing is compared with it.
By the force of the word च in the sutra, we read in the word उपमानात् also. Thus उत्तरसक्थम्, मृगसक्थम्, पूर्वसक्थम् ॥ So also in फलकमिव सक्थि = फलकसक्थम् ॥

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