भ्रातृपुत्रौ स्वसृदुहितृभ्याम्

The words भ्रातृ 'brother' and पुत्र 'son', when spoken of along with स्वसृ 'sister' and दुहितृ 'daughter' respectively are only retained and the latter are dropped.
With this sutra ceases the governing force of the remaining conditions contained in sutra 1.2.65. Even where the radical elements of two words are different there may be an ekasesha under special circumstances. Thus भ्रातृ + स्वसृ = भ्रातरौ (brother and sister or brothers). Similarly पुत्र + दुहितृ = पुत्रौ, (son and daughter or sons).

N. B.- The practical application of this sutra is very neatly illustrated by the following example. There is a verse in Yajyanvalkya smriti पत्नी दुहितरश्श्चैव पितरौ भ्रातरस्तथा which declares that on the death of a sonless person his property passes to his wife, daughters, parents and bhratarah.

Here the word bhratarah, if it be taken as simply the plural of bhratri, it means "brothers" and excludes sisters. But if it be interpreted according to this sutra, it means "brothers and sisters"; and thus gives sisters a right to inherit property of their brothers.