केशाश्वाभ्यां यञ्छावन्यतरस्याम्

Operational rule vidhi

The word केश optionally gets the प्रत्यय यञ् to indicate the meaning of 'तस्य समूहः'. The word अश्व optionally gets the प्रत्यय छ to indicate the meaning of 'तस्य समूहः'

Word by word (padaccheda)

Left context केश- अश्वाभ्याम् pañcamī · dvivacanaSubstitute / term य - छौ prathamā · dvivacanaRight context अन्यतरस्याम् saptamī · ekavacana

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.
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").

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

Pink letters are it-markers (anubandhas), tags dropped by 1.3.9. Hover or tap one for the rule that marks it, or try the it-letter finder.

Full reading

केश-अश्वाभ्याम् यञ्-छौ अन्यतरस्याम्

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

Commentary

The affixes यञ् and छ come optionally in the sense of 'collection thereof' after the words 1. केश and 2. अश्व , respectively.
Thus केशानां समूहः = कैश्यम् or कैशिकम् 4.2.47, अश्वानां समूहः = आश्वम् 4.1.63 अश्वीयम् ॥

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