अनो नुट्

The affix मत् gets the augment नुट् in the छन्दस् (Vedas) after a अङ्ग (stem) ending in अन्।
As अक्षण्वन्तः कर्णवन्तः सखायः; अस्थन्वन्तं यदनस्था बिभर्त्ति (Rig. I.164.4), अक्षण्वता लाङ्गलेन; शीर्षण्वती, मूर्द्धन्वती ॥

The word अक्षण्वत् is thus formed : अक्षि + मतुप् = अक्ष् + अन् + मत् (अनङ् is substituted for the final of akshi by 7.1.76) = अक्षमत् (the म् is elided by 8.2.7). Now we add the augment नुट् ॥ If this augment is added to मतुप्, as म्मतुप् then it becomes a portion of मतुप्, and this म् would be changed to व by 8.3.9 read with 1.1.54, and not the letter म्, because म् intervenes. If we add this augment to the end of the stem, then in अक्षण्वता &c. we cannot change it to ण because of the prohibition in 8.4.37, and the augment being नुक्, the न् would be changed to र् by 8.3.7 in सुपथिन्तरः &c 8.2.17. The first view, however, is the correct one and the difficulty in its acceptance is obviated by नुटोऽसिद्धत्वात् तस्य च वत्वं न भवति; ततः परस्य च भवति; as shown above.

The नुट् augment being considered as asiddha, is not changed to व, but the letter following it, is so changed. Thus अक्षन् 7.1.76 + मत् = अक्ष + मत् (the न् of the stem is elided by 8.2.7. Add the augment नुट् now, and we have अक्ष + न्मत् ॥ The augment according to 8.2.1, is asiddha, so that according to 8.2.9, व् is substituted for म्, and not for न्, as would have been required by 1.1.54.