The affix vic comes after the verb yaj 'to sacrifice' when upa precedes it, in the chandas (Vedas).,
As उपयङ्भिरूर्ध्वं वहन्ति 'they carry it up with the उपयज् formulas'. उपयज् is the name of eleven formulas at a sacrifice.
The word 'Chhandas' has been repeated here though the anuvritti of the word 'mantra' was present in it, in order to include the Brahmana literature also.
The च् is indicatory and is useful in including the affix विच् in the larger group called वि (which includes क्विन्, क्विप्, ण्वि, विट्), as in the sutra येरपृक्तस्य (VI. I. 67).
Why has this sutra been made, since the affix विच् would have been valid even by aphorism 75? The sutra has been separately made to show that it is a restrictive rule here. The form उपयज् is found in the Chhandas only, and not in the ordinary literature.,