नान्तादसंख्यादेर्मट्

Operational rule vidhi

The augment मट् comes before डट् in the sense of 'making full this number' after a Numeral which ends in न् when no other Numeral precedes it.

Word by word (padaccheda)

Left context नान्तात् pañcamī · ekavacanaLeft context असङ्ख्यादेः pañcamī · ekavacanaSubstitute / term म prathamā · ekavacana

Left context Pañcamī (5th case): "after X", the operation applies to what follows (1.1.67 तस्मादित्युत्तरस्य). Also used for limits and sources.
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. Hover or tap one to see its card.

Pink letters are it-markers (anubandhas), tags dropped by 1.3.9. Hover or tap one for the rule that marks it, or try the it-letter finder.

Full reading

नान्तात् असङ्ख्यादेः मट्

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

Commentary

The augment मट् comes before डट् in the sense of 'making full this number' after a Numeral which ends in न् when no other Numeral precedes it.
Thus पंचमः 'fifth' (the completer of the five), सप्तमः ॥ Why do we say 'ending in म्'? Observe विंशतेः पूरणो = विंशः 'twentieth'. Why do we say 'not preceded by a Numeral'? Observe एकादशानां पूरणं = एकादशः ॥

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