हलसीराट्ठक्

Operational rule vidhi

The affix ठक् comes in the sense of 'what bears it' after the words 1. हल and 2. सीर in Accusative -2nd case construction.

Word by word (padaccheda)

Left context हल- सीरात् 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

हल-सीरात् 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 'what bears it' after the words 1. हल and 2. सीर in Accusative -2nd case construction.
Thus हलं वहति = हालिकः a ploughman सैरिकः 'a plough ox.' The ठक् would have come by 4.3.124, the specification shows tadantavidhi and non-elision, as द्वैहालिकः, त्रैसीरिकः ॥

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