From: Rabbi Akiva Eiger
To: Rabbi Avraham Shmuel Binyamin Sofer
Rabbi Akiva Eiger resolves his grandson's challenge to the Rivash's principle that rov cannot override two chazakos, explaining that even so a safek results, and showing how this resolves Tosfos's difficulties in the tinok etzel isah sugya. He further resolves a secondary problem regarding nikvas ha'veshet by distinguishing it as a miut d'miuta — an exceedingly rare minority — even among treifos, though he does not issue a definitive ruling.
Source: Shu"t Rabbi Akiva Eiger §198