Michael M. Richter (21 June 1938 – 10 July 2020) was a German mathematician and computer scientist. Richter is well known for his career in mathematical logic, in particular non-standard analysis, and in artificial intelligence, in particular in knowledge-based systems and case-based reasoning (CBR, Fallbasiertes Schließen). He is worldwide known as pioneer in case-based reasoning. Life Richter was born in Berlin into an educated family: his father was Dr. Paul Kurt Richter, a literary scientist; his grandfather was Dr. Carl Greiff, a medical scientist (in 1940, Greiff published a 544 pages book called Diabetes-Probleme with the publisher Johann Ambrosius Barth). Richter studied mathematics 1959–1965 at the University of Münster and the University of Freiburg, where he completed his Ph.D. in Mathematical Logic under the supervision of Walter Felscher and he obtained his Habilitation in 1973 in Mathematics at the University of Tübingen. After teaching at the University of Texas at Austin, he was Professor for Mathematics at the RWTH Aachen from 1975 to 1986. In 1986, he accepted a chair for Computer Science at the University of Kaiserslautern where he taught until his retirement in 2003. During his academic career, he held visiting positions at Austin, Florianópolis and Calgary; he was also teaching at the University of St. Gallen from 1994 to 2000. Finally, he was Adjunct Professor at the University of Calgary and Visiting Professor at the Universidade Federal de Santa Catarina, Florianópolis, Brazil. He had 65 doctoral students and 296 Masters' students during his career, many of which now hold tenured academic positions in various parts of the world. He is the author of nine books the most recent of which is Case-Based Reasoning: A Textbook published with Springer Verlag. His son Peter P. Richter (born 1976) is a geologist with a doctoral degree from the University of Mainz, currently employed at the University of Kiel. He died on 10 July 2020 at the age of 82. Activities From 1981 to 1985 Michael Richter was President of the Deutsche Vereinigung für mathematische Logik und für Grundlagenforschung der exakten Wissenschaften (DVMLG). Starting 1987 he was for five years co-initiator and co-chair of an annual series of conferences Logic in Computer Science. In 1989 Michael Richter became head of the research group Mathematical Logic (until 2004) from the Heidelberg Academy of Sciences (Heidelberger Akademie der Wissenschaften). There he continued and extended the Omega Bibliography, a worldwide unique scientific collection containing