The affix ghañ comes after the verbs 1. śri 2. yu 'to join' 3. pū 'to purify' 4. dru 'to run' when the preposition ut is in composition.,
This debars the affix ach 3.3.56. Thus उच्छ्रायः 'rising of a planet'; उद्यावः 'mixing'; उत्पावः 'purifying ghee'; and उद्रावः 'flight'.
How do you explain the form समुच्छ्रयः in पतनान्ताः समुच्छ्रयाः ? The word विभाषा 'optionally' in the next sutra, exerts a retrospective effect on this sutra, and the form is an optional one. This is a most unusual thing and is called सिंहावलोकनन्यायः 'the maxim of the lion's backward glance'. It is used when one casts a retrospective glance at what he has left behind, while at the same time he is proceeding, just as the lion, while going onward in search of prey, now and then bonds his neck backwards to see if any thing be within its reach.,