Reference for Bava Batra 103:6
ולא לאב בנכסי הבן ולא לבן בנכסי האב: אמר רב יוסף אפילו חלקו רבא אמר חלקו לא
however, said that if they have parted the rule no longer applies. R. Jeremiah of Difti said: In a case which occurred, R. Papi decided according to the ruling of Raba. R. Nahman b. Isaac said: I have been told by R. Hiyya from Hormiz Ardeshir,<span class="x" onmousemove="('comment',' Ardeshir was a town not far from Ctesiphon. 'Hormiz Ardeshir' may have been a village in the neighbourhood. ');"><sup>9</sup></span> who was told by R. Aha b. Jacob in the name of R. Nahman b. Jacob, that if they [the father and son] have parted, the rule [of the Mishnah does] not apply.<span class="x" onmousemove="('comment',' I.e., they have hazakah against one another. ');"><sup>10</sup></span>