आदिश्चिहणादीनाम्

Operational rule vidhi

In a Neuter तत्-पुरुष समास ending in कन्था the first syllable of चिहण etc. have the acute accent (उदात्त).

Word by word (padaccheda)

Substitute / term आदिः prathamā · ekavacanaTarget चिहणादीनाम् ṣaṣṭhī · bahuvacana

Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).

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

Full reading

आदिः चिहणादीनाम्

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

As a rewrite rule (sketch from case endings)

चिहणादीनाम् → आदिः

Replace cihaṇādīnām with ādiḥ. Inherited words (anuvṛtti) may add further conditions.

Commentary

In a Neuter तत्-पुरुष समास ending in कन्था the first syllable of चिहण etc. have the acute accent (उदात्त).
As चि꣡हणकन्थम्, म꣡डरकन्थम्, म꣡डुरकन्थम् ॥ The repetition of the word आदि in this sutra, though its anuvritti was present, indicates that the first syllable of the first member gets the acute. The word चिहण is derived from the root चिनोति with क्विप् which gives चित् an हन is formed by adding अच् 3.1.134 to हन् ॥ चित् + हन = चिहण the elision of त् is irregular.

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