He spent the last part of his life working on his own approach to set theory, logic and arithmetic, which was published in 1914, the year after his death.
Siya na nagastos sa huling bahagi ng kanyang buhay ang pagtatrabaho sa kanyang sariling diskarte sa set theory, lohika at arithmetic, na kung saan ay nai-publish sa 1914, ang taon pagkatapos ng kanyang kamatayan.