fl. 1130s-1140s

Spanish scholar who translated several mathematical works, and added new terms to the vocabulary of mathematicians. A converted Jew, Johannes, sometimes called John of Luna or John of Seville, worked with the archdeacon of Segovia, Domengo Gondisalvi, on translating the works of ancient Greek and medieval Arab mathematicians and scientists. In about 1134, he translated a version of Ptolemy's (c. 100-170) Almagest, thereby influencing the exposure of that seminal work to European scholars. He was the first to use the term numerus minuendus (number to be diminished), which eventually became the English minuend, and he was one of the first to use the word fractiones.