Complex sentence: From 1997 to 2003 he was an assistant professor at the University of New Mexico, Gallup, and in 2003 he was promoted to Associate Professor of Mathematics; he is currently chairman of the Gallup Branch Department of Mathematics and Sciences.
Split into simpler sentences: From 1997 to 2003 he was an assistant professor at the University of New Mexico, Gallup. He was promoted to Associate Professor of Mathematics in 2003; he is currently chairman of the Gallup Branch Department of Mathematics and Sciences.