श्नाऽभ्यस्तयोरातः

Operational rule vidhi

The आकार of the विकरण श्ना and also of an अभ्यस्त is removed when followed by a सार्वधातुक कित् and ङित् प्रत्यय.

Word by word (padaccheda)

Target श्ना- ṣaṣṭhī · dvivacanaTarget आतः ṣaṣṭhī · ekavacana

Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).

Dotted words are technical terms. Hover or tap one to see its card.

Full reading

श्ना- आतः

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

Commentary

Before a सार्वधातुक कित् or ङित् affix beginning with a vowel, the long आ of श्ना (the विकरण of the क्र्यादिगणः (9th Conjugation)) and of the reduplicate अङ्ग (stems) is elided.
Thus लुनते, लुनताम्, अलुनत; मिमते, मिमताम्, अमिमत, संजिहते, संजिहताम् and समजिहत ॥ Why do we say 'of श्ना and the reduplicates'? Observe यान्ति, वान्ति ॥ Why 'of long आ'? Observe बिभ्रति ॥ Why 'before कित् and ङित्'? Observe अलुनात्, अजहात् ॥

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