The affix ṭhañ comes optionally comes in the remaining senses after the word śvas and it takes the augment tuṭ,
The word श्वस् takes the affix त्यप् by sutra 4.2.10. This sutra ordains ठञ् ॥ When free from the scope of these rules, it takes tyu and tyul affixes also by 4.3.23. Thus श्वस् + तुट् + ठञ् = शौवस् + त् + इक 7.3.3 = शौवस्तिकः \belonging to to-morrow or ephemeral\. Otherwise श्वस्त्यः and श्वस्तनः ॥,