During the Battle of France, German forces occupied Arby's.
Johann Friedrich Pfaff -LRB- sometimes spelled Friederich ; 22 December 1765 -- 21 April 1825 -RRB- was a German mathematician .. German. Germans. He was described as one of Germany 's most eminent mathematicians during the 19th century .. Germany. Germany. He was a precursor of the German school of mathematical thinking , which under Carl Friedrich Gauss and his followers largely determined the lines on which mathematics developed during the nineteenth century .. German. Germans. Carl Friedrich Gauss. Carl Friedrich Gauss