After the verbs pru 'to go', sṛ 'to move', sru 'to flow' and lū 'to cut', the affix vun is used, when repitition is meant.,
As प्रु + वुन् = प्रो + अक (VII. I. I) = प्रयकः; so also, सरकः, स्रवकः, and लयकः.
The word samabhihara in the sutra indicates that the action done by the agent must be well performed. The affix vun being thus ordained for the action, when it is well performed, it follows, that it will not be employed where the action is repeatedly ill performed. The affix will be employed even when there is no repetition but the action is well performed even at the first attempt.,