यसोऽनुपसर्गात्

Operational rule vidhi

In presence of a सार्वधातुक प्रत्यय in the कर्तरि प्रयोग, the verb यस् when used without an उपसर्ग gets the श्यन् विकरण optionally.

Word by word (padaccheda)

Left context यसः pañcamī · ekavacanaLeft context अनुपसर्गात् pañcamī · ekavacana

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

यसः अनुपसर्गात्

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

Commentary

The affix श्यन् is optionally used after the verb यस् 'to strive' when it is used without a preposition and when a सार्वधातुक affix denoting an agent, follows.
Thus यास्यति or यसति 'he strives'. But no option is allowed in आयस्यति, प्रयस्यति. The root यस् belongs to the Divadi class.

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