ר' אבא בר יעקב

Rabbi Abba bar Yaakov said in the name of Rabbi Yochanan [Gittin (59a), Bava Metzia (38b), and Jerusalem Talmud, Chapter 7 of Kilayim, and in Tosafot Sukkah (30b), and the Resh Galuta said to examine the law of a person who killed another, and Rav Pappi refuted his ruling, and exempted Rav Pappi from the Sanhedrin's punishment (Ketzot 27a), in the name of Rabbi Yitzchak Ruba, Jerusalem Talmud, Chapter How to Bless, Mishnah A].