Immanuel Bonfils

Immanuel ben Jacob Bonfils was a French-Jewish mathematician and astronomer in medieval times who flourished from 1340 to 1377, a rabbi who was a pioneer of exponential calculus and is credited with inventing the system of decimal fractions. He taught astronomy and mathematics in Orange and later lived in Tarascon, both towns in the Holy Roman Empire that are now part of modern-day France. Bonfils studied the works of Gersonides, the father of modern trigonometry, and Al-Battani and even taught at the academy founded by Gersonides in Orange.