Russells Paradox Cards

Description: "The paradox that shook the foundations of mathematics. A gold set half in and half out of itself, among ordinary sets, captures the moment naive set theory broke and modern logic was born. Russell's paradox (1901): the set R of all sets that do not contain themselves. Does R contain R? Shown as a set straddling its own boundary, with R = {x | x ∉ x} and R ∈ R ⟺ R ∉ R. For mathematicians, set theory and logic students, computer scientists, philosophy teachers and fans of the barber paradox. A brainy gift for anyone who loves foundations of math.