Returning to Nancy, he was professor there in the Faculty of Science from 1948 to 1952 when he accepted a one year appointment as professor of mathematics at the University of Michigan.
Bumabalik sa Nancy, siya ay propesor doon sa Faculty of Science mula sa 1,948 sa 1952 kung kailan siya tinanggap ng isang taon appointment bilang propesor ng matematika sa University of Michigan.