A: Bezirk Friedrichshain-Kreuzberg, Berlin, Berlin, Germany
In 1915 German mathematician Leopold Löwenheim of Berlin published Über Möglichkeiten im Relativkalkül, containing the first appearance of what is now known as the Löwenheim-Skolem theorem, the first theorem of modern logic, anticipating Kurt Gödel’s completeness theorem of 1930. Löwenheim's paper was first published in Mathematischen Annalen 76 (1915) 447-470. A summary and English translation are in van Heijenoort, From Frege to Gödel (1967) 228-51.