Samkhya treatise of Vindhyavasin 2.5: Tattvasaṃgrahapañjikā

2.5

yad eva dadhi tat kṣīraṃ yat kṣīraṃ tad dadhīti ca /
vadatā rudrilenaiva khyāpitā vindhyavāsitā //

By asserting that 'whatever is curd is milk, and whatever is milk is curd,' / Rudrila has indeed made known his status as a follower of Vindhyavāsin.

"What is curd is milk, and what is milk is curd": by saying this, Rudrila has shown himself a dweller in the Vindhya [wilds].