After ṭu final in a pada , the change of a dental (stu) to a cerebral (ṣṭu), does not take place, except in the case of the affix nām,
Thus श्वलिट् + साये = श्वलिट्साये, मधुलिट्साये, श्वलिट्तरति, मधुलिट्तरति ॥
Why do we say पदान्तात् 'final in a Pada'? Observe ईड् + ते = ईड् + टे = ईट्टे ॥
Why do we say टोः 'after टु' Observe सर्पिष् + तमम् = सर्पिष्टमम् ॥
Why do we say अनाम् 'except in the case of the affix nam'? Observe षट् + नाम् = षण्णाम् ॥ This exception is very inadequate. Hence the following
Vart:- It should be stated rather that नवति and नगरी as well as नाम् are not prevented from undergoing the cerebral change. As, षण्णाम् 'of six', षण्णवतिः ninety-six, and षण्णगरी 'six cities.',