2 search results - page 1 / 1 » The Ultrafilter Closure in ZF |
MLQ
2010
13 years 9 months ago
2010
: It is well known that, in a topological space, the open sets can be characterized using filter convergence. In ZF (Zermelo-Fraenkel set theory without the Axiom of Choice), we c...
MLQ
2000
13 years 10 months ago
2000
In Zermelo-Fraenkel set theory with the axiom of choice every set has the same cardinal number as some ordinal. Von Rimscha has weakened this condition to "Every set has the s...