When the sarvanāma adas does not end in s then there is substituted u or ū for the vowel after d , and m for d,
Karika :-
अदसोद्रे पृथङ् मुत्वं के चिदिच्छन्ति लत्ववत् ।
के चिदन्त्यसदेशस्य नेत्येकेऽसेर्हि दृश्यते ॥
Thus अमुम्, अमू, अमून्, अमुना, अमुभ्याम् ॥ अद is substituted for अदस् before a case-ending by 7.2.102, which in Feminine becomes अदा ॥ By the present sutra read with 1.1.50, अमु is substituted for अद and अमू for अदा ॥ The उ which replaces one-matra vowel will be one-matra उ i. e. short उ, and the उ which replaces a two-matra vowel will be a two-matra उ i. e. long ऊ ॥ See 1.1.50.
Why do we say,
ot ending in स\? Observe अद इच्छति = अदस्यति ॥ Objection:- How can this be a valid example, as the word पदस्य is understood here, and अदस् before the affix क्य is not a pada 1.4.15? Answer:- This indicates that the मु change takes place, even when अदस् is not a pada. As अमुमुय ॥
Vart:- It should rather be stated that the rule applies to that अदस् which has no ओ, or स् or र् ॥ So that the prohibition may apply to अदोऽत्र, अदः कुलम् ॥ The visarjaniya being considered as asiddha, this word is considered as ending in र् ॥
In order to apply the prohibition to ओ and र् also, some explain the sutra thus :- अः सेर्यस्य सोयमसिः, यत्र सकारस्य अकारः क्रियते ॥ \The word असिः in the sutra is a Bahuvrihi, and means that in which अ is substituted for स\ ॥ The sutra is thus confined to the form अद derived by changing the स् into अ by 7.2.102: and not to any other अद ॥
When अदस् takes the final-substitute अद्रि by 6.3.92, how is this rule to be applied ? Thus by 3.2.59, the root अञ्च् takes क्विन् ॥ We compound it with अदस्, as अदाऽञ्चति ॥ अदस् + अञ्च + क्विन् = अद् + अद्रि + अञ्च् + क्विन् 6.3.92 = अदद्र्यच् 6.4.24. Now there are three views, (1) the द of अद, and द्र, of अद्रि are both changed to मु by the present sutra; (2), the first द is not changed, but only द्र; (3) none is changed. Thus we have (1) अमुमुयङ् 7.1.70, (VI. I. 68), 8.2.23 and 7.2.62, अमुमुयञ्चौ, अमुमुयञ्चः ॥ (2) Secondly, अदमुयङ् अदमुयञ्चौ, अदमुयञ्चः ॥ (3) Lastly अदद्र्यङ्, अदद्र्यञ्चौ, अदद्र्यञ्चः ॥ The above verse summarises this:
\Some ordain that मु should come separately for both adas and adri, as there is double ल (in चलीक्लृप्यते); others would have मु only for the last portion which stands in proximity to the final, (i, e. for द्र); while a third class would have nowhere, because they explain असेः of the sutra, by confining it to: 7.2.102.\ The first class interpret असेः by \that form of अदस् which has no स्\; and they do not apply the maxim अनन्त्यविकारेऽन्त्यसदेशस्य कार्यं भवति \when a modification is ordained with regard to some thing which is not final, the operation takes place on that only which is in proximity to the final.\ The second class apply this maxim and make मु change only for द्र which stands in proximity to the final; while the last class interpret the word असेः in a different way altogether (अः अस्य सकारस्य सोऽयम् असिः) ॥
Why do we say दात् 'for the vowel after द'? Observe अमुया, अमुयोः, the final य as not changed to उ ॥,