who, in a work published in 1832 but probably dating from 1823, announced his discovery of non-Euclidean geometry. His work was independent of Lobachevsky. He had persisted with the problem, while serving as an army officer, despite the warnings of his father, an eminent mathematician and friend of Gauss, who had himself spent many years on it without success. Later, János was disheartened by lack of recognition.