He is the alphabetically former namesake of an axiom of choice-dependent paradox in which a ball can be decomposed and reassembled into two copies of itself.
Baire's category theorem can be used to prove the open mapping theorem named for this mathematician and Schauder, and the uniform boundedness principle named for him and Steinhaus. He is the alphabetically former namesake of a theorem that allows bounded linear functionals to be extended to a whole space; that theorem is named along with Hahn. Complete (*) normed vector spaces are named for this mathematician, who showed that, on those spaces, if there is a contraction mapping from a closed subset into itself, then there is a fixed point. He is the alphabetically former namesake of an axiom of choice-dependent paradox in which a ball can be decomposed and reassembled into two copies of itself. For 10 points, name this Polish mathematician who names a paradox with Alfred Tarski.
Baire's category theorem can be used to prove the open mapping theorem named for this mathematician and Schauder, and the uniform boundedness principle named for him and Steinhaus.
Stefan Banach