अजाद्यदन्तम्

Operational rule vidhi

In a द्वन्द्व compound, let a what begins with a vowel and ends with a short अ be placed first.

Word by word (padaccheda)

Substitute / term - आदि- अत्- अन्तम् prathamā · ekavacana

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

-आदि-अत्-अन्तम्

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

Commentary

In a द्वन्द्व compound, let a what begins with a vowel and ends with a short अ be placed first.
Thus, उष्ट्रखरम् 'the camel and the ass.' उष्ट्रशशकम् 'the camel and the hare.'

Why do we say 'अत् with a त्' 1.1.70? This rule does not apply when it is long आ as अश्वा + वृषः = अश्वावृषौ or वृषाश्वे .

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