רב אחא ברב עויא

Rab Acha bar Rav Ovia [(and in our version, Ovia) and in Menachot (37b) it should be Rav Acha, son of Rav Ovia, and Rabbi Chiya, and so it is in the new Shas. Rabbi Asi said in the name of Rabbi Yochanan in Pesachim (24b)]. He sat before Rav Asi [Yevamot (117a). And he said in the name of Rav Asi bar Chanina.

He found the students of Rav Ashi in Eruvin (11b)], and he said to Rav Ashi [Nedarim (35a, 51b) and Chulin (Chapter 1) Pesachim (44b) Bava Batra (Chapter 2) Bava Metzia (96a) Eruvin (48b) Nazir (37a) Bava Batra (3a, 46b, 190a) and in Chapter 23 (Eruvin 74b) Rav Ashi bar Rav Ovia is a mistake in the Rif, for in the Gemara it is corrected to Rav Acha bar Rav Ovia. And in Bava Kamma (62a) it is Rav Ada bar Rav Ovia to Rav Ashi, which is a mistake; he challenged Rav Ashi in Ketubot (76a).

And it seems that the aforementioned Rav Ashi is the ancient Rav Ashi]. Before Rav Chisda, in the name of Rabbi Yochanan, Rav Chisda said to him, "Who obeys you and your teacher Rabbi Yochanan?" [Pesachim (30b). He said to Rav Menashe in Chulin (31a)]: