Józef Schreier (Polish pronunciation: [ˈjuzɛf ˈʂrajɛr]; 18 February 1909, Drohobycz, Austria-Hungary – April 1943, Drohobycz, Occupied Poland) was a Polish mathematician of Jewish origin, known for his work in functional analysis, group theory and combinatorics.
In his first published paper, he defined what later came to be known as Schreier sets in order to show that not all Banach spaces possess the weak Banach-Saks property, disproving a conjecture of Stefan Banach and Stanisław Saks.
[1][2] Schreier completed his master's degree On tournament elimination systems in 1932 under the direction of Hugo Steinhaus.
Schreier correctly conjectured that to determine the second largest number in an unordered list requires at least
I believe that some of our papers were among the first to show applications to a wider class of mathematical objects of modern set theoretical methods combined with a more algebraic point of view.
[7]With the outbreak of World War II, Eastern Poland including Drohobycz was occupied by the USSR in accordance with the Molotov–Ribbentrop Pact.
In April 1943, the Germans discovered—or were informed of—an underground bunker in which Schreier was hiding with other Jews.