252. By a process

By a process of abbreviation essentially akin with that of ar or ra to ṛ, the va (usually initial) of a number of roots becomes u, and the ya of a much smaller number becomes i, in certain verbal forms and derivatives. Thus, from vac comes uvā́ca, ucyā́sam, uktvā́, uktá, uktí, ukthá, etc.; from yaj come iyā́ja, ijyā́sam, iṣṭvā́, iṣṭá, íṣṭi, etc. See below, under the various formations.

a. To this change is given by European grammarians the name of samprasāraṇa, by adaptation of a term used in the native grammar.