6.2.157
अच्कावशक्तौ
Operational rule vidhi
A word formed with the कृत् affixes अच् and क preceded by the particle नञ् has the acute accent (उदात्त) on the final when the meaning is 'not capable'.
Word by word (padaccheda)
Substitute / term अच्कौ prathamā · dvivacanaRight context अशक्तौ saptamī · ekavacana
- 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").
Full reading
अच्कौ अशक्तौ
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
A word formed with the कृत् affixes अच् and क preceded by the particle नञ् has the acute accent (उदात्त) on the final when the meaning is 'not capable'.
Thus अपचः꣡ = य पक्तुं न शक्नोति, so also अजयः꣡, अपठः꣡, अविक्षिपः꣡, अविलिखः꣡ 3.1.134 &c)). Why do we say when meaning 'not capable'? Observe अपचो दीक्षितः, अपचः परिव्राजकः ॥ A दीक्षित and a परिव्राजक do not cook their food, not because they are physically incapable of cooking, but because by the vows of their particular order they are prohibited from cooking.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.