We recently wrote about how infinitely large sets are not all the same size as each other, but we were a bit vague about what we meant by a set. The people who invented set theory also started out ...

Mathematics often helps us to think about issues that don’t seem mathematical. One area that has surprisingly far-reaching applications is the theory of sets. Sets are one of the most basic ...

Fraenkel-Mostowski set theory represents an alternative set theory with multiple applications in mathematics and computer science. It deals with ‘finitely supported sets’ instead of ‘sets’.

When you can exactly match each element of one set with an element in the other, that’s a strong form of equivalence. But in an area of mathematics called homotopy theory, for example, two shapes (or ...

Gregory H. Moore, The Origins of Zermelo's Axiomatization of Set Theory, Journal of Philosophical Logic, Vol. 7, No. 1 (Jan., 1978), pp. 307-329 ...