One can't construct ultrafilters
113863
The non-existence of non-principal ultrafilters in ZF
88087
Why does this say there is no join predicate?
132382
Showing a set is nowhere dense in $C([0,1])$
94771
Not every boolean function is constructed from $\wedge$ (and) and $\vee$ (or)
53363
Ultralimit of an eventually constant generalized sequence
70152
Can't delete question filters; fails silently
70936
Blocking Dataset`$ElisionThreshold doesn't work
116676
Examples of uncountable sets with zero Lebesgue measure
94203
Examples for almost-semirings without absorbing zero
14994
Showing a function $f$ cannot be surjective
70413
A vector space over $R$ is not a countable union of proper subspaces
62793
$\mathbb{R}$ with the lower limit topology is not second-countable
67064
Uncountable minus countable set is uncountable
78404
How to avoid infinite recursion with super()?
75019
Infinite Cartesian product of countable sets is uncountable
83907
$f$ bounded but $f'$ isn't
142503
There are no compact minimal surfaces