Stefan Banach (March 30, 1892 - August 31, 1945) was a Polish mathematician. He is one of the founders of modern functional analysis and is often considered one of the most important mathematicians of our time. His famous book Theory of Linear Operations was published in 1932. The Hahn–Banach theorem is one of the fundamental theorems of functional analysis.Banach is mentioned as possibly autistic in Autism in Mathematician by Ioan James. Read more about this great mathematician on his Wikipedia page.