And after the verbs which take the words itaretara 'each other' and anyonya 'one another', as upapada (or dependant qualifying words), the affixes of ātmanepada are not used, though reciprocity of action be denoted.,
Thus इतरेतरस्य व्यति लुनन्ति 'they cut each other' अन्योन्यस्य व्यतिलुनन्ति 'they cut one another.'
Vart:- This rule must also be applied when the word परस्पर is in composition with the verb, as an upapada. As परस्परस्य व्यतिलुनन्ति.,