He then taught mathematics at the high school level until 1937, when he obtained a faculty position at Charles University. When the German army invaded Czechoslovakia in 1938, Wolf obtained an invitation to visit the Mittag-Leffler Institute in Sweden; he remained in Sweden as part of the underground resistance to the Germans until 1941 before emigrating to the United States. He taught at Macalester College for a year, and then joined the faculty of the University of California, Berkeley in 1942.
After teaching mathematics at the high school level until 1937, Wolf took a position at Charles University. When Germany invaded Czechoslovakia in 1938, he was invited to Sweden's Mittag-Leffler Institute and remained there as part of the resistance movement against the Germans until 1941 before moving to the United States. He taught at Macalester College for one year and then joined the faculty of the University of California, Berkeley in 1942.