पञ्चमी विभक्ते

Operational rule vidhi

The 5th case-affix is used when the thing specified is different or divided from (and not included in) that from which specification is intended.

Word by word (padaccheda)

Substitute / term पञ्चमी prathamā · ekavacanaRight context विभक्ते 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

पञ्चमी विभक्ते

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

Commentary

The 5th case-affix is used when the thing specified is different or divided from (and not included in) that from which specification is intended.
This debars the sixth and the seventh case-affixes, as, माथुराः पाटलिपुत्रेभ्यः सुकुमारतराः 'Mathura is more beautiful than Pataliputra.'

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