This answer cites a verse supposedly written by Madhavacharya:
Swami Vidyaranya (aka Madhavacharya) the 12th Jagadguru of Śringeri Śarada Pītham from 1380-1386 who is credited for founding the Vijayanagara empire, enumerates five conditions for someone to be considered a Hindu
गोभक्तो भारतगुरुर्हिन्दुर्हिंसनदूषकः |”
The above translates to that
He who 1) believes in “Omkar” mantra 2) has firm faith in reincarnation (by extension law of karma) 3) venerates cows 4) considers Bharat to be a holy land and 5) keeps away from himsa, is considered to be Hindu
Some people say it's found in Madhavacharya's Shankara Digvijayam but I can't find it in the English translation by Swami Tapasyananda. Others attribute it to Madhavacharya without mentioning the source. Which makes me wonder if Madhavacharya is really the author of this verse.
If Madhavacharya is indeed the author of this, which of his works has the verse?