Perfect of Vedic i-

This is partly a test to see if one can use this group for these kind
of questions.

My questions is: the Vedic perf. of i "go" is iyâya (3.sg.) and îyúr
(3.pl), how have these forms developed? If we follow LIV's
reconstruction *h2ej-, I would expect a development *h2e-h2oi- > *Ha-
ai- > *ai-/âi- > Vedic *e-/ai-/ây (2.sg. *e-tha or *aitha, 3.sg. *ây-
a)

Does anybody have the explanation?