Leen Ammeraal is a retired lecturer of Hogeschool Utrecht, The Netherlands, where he was employed from 1977 to 1998. He has a degree (ir.) in mathematics at University of Technology Delft, The Netherlands. He worked as a programmer and mathematician at Akzo Research and Engineering, Arnhem, The Netherlands, from 1961 to 1972 and did research work on compilers from 1972 to 1977 at Mathematical Centre, Amsterdam. He wrote many books for Wiley (as well as for the Dutch publisher Academic Service). Some of his Wiley books have been translated into other languages (Japanese, Russian, Italian, French, German, Greek, Danish, Portuguese, Bulgarian).