अचित्तहस्तिधेनोष्ठक्

Operational rule vidhi

For the words that represent non-living entities, and also for the words हस्तिन् and धेनु, the प्रत्यय ठक् is used to indicate the meaning of 'तस्य समूहः'.

Word by word (padaccheda)

Left context अ- चित्त- हस्ति- धेनोः pañcamī · ekavacanaSubstitute / term 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

अ-चित्त-हस्ति-धेनोः ठक्

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

Commentary

The affix ठक् comes in the sense of 'collection thereof' after the names of things without consciousness and after 1. हस्ति and 2. धेनु।
This debars अण् and अञ् ॥ The अपूपानां समूहः = आपूपिकम् ॥ The affix ठक् is replaced by इक् 7.3.50 or क 7.3.50. Thus हास्तिकम्, धेनुकम्, शाष्कुलिकम् ॥

Vart:- Not so, if the word धेनु is preceded by the negative particle नञ् ॥ As आधेनवम् (See IV. 2.45).

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