A number of roots having ya after a first initial consonant take i (from the y) instead of a in the reduplicating syllable: thus, from √vyac comes vivyac; from √pyā comes pipyā.

a. These roots are vyac, vyath, vyadh, vyā, jyā, pyā, syand; and, in the Veda, also tyaj, with cyu and dyu, which have the root-vowel u. Other sporadic cases occur.

b. A single root with va is treated in the same way: namely svap, which forms suṣvap.

c. These roots are for the most part abbreviated in the weak forms: see below, 794.