There is not the substitution of ā for the diphthong of the root vye when the affixes of the Perfect follow.,
Thus संविव्याय, संविष्ययिथ ॥ The reduplicate of the Perfect is vocalised here by (VI. I. I7). The Vriddhi in संविव्याय takes place by 7.2.115 before the णित् affix णल् ॥,