As part of the German war effort, he took up a teaching post as a Dozent in the Mathematical Institute of the German University of Prague and he taught there until arrested and taken into custody.
Bilang bahagi ng German digma pagsisikap, siya took up ng pagtuturo-post bilang isang Dozent sa matematika Institute ng German Unibersidad ng Prague at siya nagtuturo mayroon hanggang madakip at kinuha sa bilangguan.