What is "simlai"

Rabbi Simlai was a talmudic sage who lived in Israel in the 3rd century. The calculation of 613 Mitzvot is attributed to him. He was a student of Rabbi Judah II, the grandson of Judah I, the author of the Mishnah. A famous Haggadist, Simlai endeavored to induce Judah II to abrogate the prohibition against using bread prepared by pagans.