רב אבא אבוה דרב בריה דרב משרשיא

Rab Abba, the father of Rav, the son of Rav Mesarshiya [thus we state in the name of Rabba in Eruvin (24a) that there are two printed versions and there are typographical errors here. I have seen in the genealogies the letter Mem, Rav Mesarshiya, the son of Rav, in the chapter "Ossin Pesin," thus it is written. Perhaps it should be Rabbi Abba, the father of Rav, the father of Rav Mesarshiya, or Rabbi Abba, the son of Rav Mesarshiya, and in Shas it was not corrected.

Alternatively, we find Rav Acha, the son of Rav, and likewise his son Rav Mesarshiya (see there), and perhaps Rav Acha, the son of Rav, had a son named Rav after his father. And for this Rav, there was a son named Rav Mesarshiya, and it should be Rav Acha, the father of Rav (who was) the father of Rav Mesarshiya (see above, Rav Bibi, the son of Rav Mesarshiya)].