The affix aṇ (a) comes without changing the sense, after a stem ending in the affix iṇun,
By 3.3.44, the affix इनुण् is added to a root to express a condition resulting from a universal co-operation of the action denoted by the root. But a word formed by इनुण् is after all an imaginary word, it requires the further addition of this affx अण् to make it a complete word. In fact, all svartha affixes generally complete the not fully developed word. Thus सांराविणम् वर्त्तते, सांकूटिनम् ॥,