After the word ubha , ayac is always the substitute for tayap , having the udātta (acute accent) on its first syllable.,
The affix अय꣡च् having indicatory च् takes the acute accent on the final syllable 6.1.163, i. e. on य, the special mention of the udatta in the sutra shows that the accent should be on a syllable which would otherwise not have taken it i. e. the first syllable i. e. अ; for had this not been the meaning, there was no necessity of using the word udatta in the sutra.
If उभ is a Sankhya word (1. 1. 23) in the secular sense, it would have taken तयप्, the present sutra ordains अय꣡ instead as a substitute always. If it is not a Sankhya, then we should first ordain तयप् after it, by the process of splitting the sutra 5.2.42 ante into two, thus संख्यायाः तयप्, अवयवे तयप् and then replace तयप् by अय꣡ ॥
Thus उभौ पीतलोहितौ अवयवौ यस्य = उभयः ॥ उभ꣡ये देवमनुष्याः; उभ꣡योः मणिः ॥,