The affix añ comes in the quadruple sense after a polysyllabic prātipadika (Nominal Stem) when 'a well' is to be designated.,
This debars अण्. Thus दीर्घवरत्रेण निर्वृत्तः कूपः = दैर्घवरत्रः \a well completed by Dirghavaratra\. So also कापिलवरत्रः ॥,