5.1.121
न नञ्पूर्वात्तत्पुरुषादचतुरसंगतलवणवटयुधकतरसलसेभ्यः
Operational rule vidhi
The affixes denoting 'nature' taught hereafter do not come after a तत्-पुरुष compound formed by the negative particle नञ् with the exception of the the following - 1. चतुर 2. संगत 3. लवण 4. वट 5. बुध 6. कत 7. रस and 8. लस .
Word by word (padaccheda)
Indeclinable न avyayaLeft context नञ्पूर्वात् pañcamī · ekavacanaLeft context pañcamī · ekavacanaLeft context अ- चतुर- संगत- लवण- वट- युध- कत- रस- लसेभ्यः pañcamī · bahuvacana
- Indeclinable An avyaya such as च "and", वा "optionally", न "not".
- Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
Dotted words are technical terms. Hover or tap one to see its card.
Full reading
न नञ्पूर्वात् अ-
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
The affixes denoting 'nature' taught hereafter do not come after a तत्-पुरुष compound formed by the negative particle नञ् with the exception of the the following - 1. चतुर 2. संगत 3. लवण 4. वट 5. बुध 6. कत 7. रस and 8. लस ।
Thus the words अपति, अपटु and अरमणीय will have two forms only i.e. अपतित्वम् or अपतिता, अपटुत्वम् or अपटुता, अरमणीयत्वम् or अरमणीयता ॥ While by 5.1.128, other compounds will have यक् also, as सैनापत्यम् ॥ An exception to this is आविदूर्य 7.2.25, as used by the author himself. Why do we say नञ् पूर्वात् "a Tatpurusha whose first member is नञ्"? Observe बार्हस्पत्यम्, प्राजापत्यम् ॥
Why do we say 'after a Tatpurusha?' Observe, when the word अपटु is a Bahuvrihi compound meaning नास्य पटवः सन्ति, its derivative will be आपटवम्. So also, आलाघवम् ॥
So also the compounds of चतुर &c, with नञ्, e.g. आचतुर्यम्, आसंगत्यम्, आलवण्यम्, आवट्यम्, आबुध्यम्, आकत्यम्, आरस्यम्, आलस्यम् ॥ In some texts, there is युध instead of बुध ॥
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.