Complex sentence: From 1964 until 1980, Halberstam was a Professor of Mathematics at Nottingham University; in 1980, he took up a position at the University of Illinois, Urbana Champaign (UIUC); he became an Emeritus Professor at UIUC in 1996.
Split into simpler sentences: From 1964 until 1980, Halberstam was a Professor of Mathematics at Nottingham University. In 1980, he took up a position at the University of Illinois, Urbana Champaign (UIUC) and he became an Emeritus Professor at UIUC in 1996.