A dense, uncountable subset of reals whose complement is also dense and uncountable in every interval
129205
A question about uncountable, dense sets in R
119649
Every metrizable space with a countable dense subset has a countable basis
95294
Dense subset of $C[0,1]$ which preserves rationals
57839
Real analysis: density and continuity
7402
Showing a compact metric space has a countable dense subset
127575
Prove that Open Sets in $\mathbb{R}$ are The Disjoint Union of Open Intervals Without the Axioms of Choice
83842
Alternate proofs (other than diagonalization and topological nested sets) for uncountability of the reals?
102250
Subset of $C[0,1]$ is nowhere dense
44522
Subsets of the reals when the Continuum Hypothesis is assumed false
139826
arbitrary large finite sums of an uncountable set.
136106
Is every open subset of $ \mathbb{R} $ uncountable?
14972
Cardinality of Vitali sets: countably or uncountably infinite?
121831
Proving that rational numbers are dense
88079
R has an uncountable number of distinct dense subsets.
67702
Minimal dense subset
73154
Compact subset in colimit of spaces
152976
Real Analysis: open and closed sets