A subset of $[0,1]\times[0,1]$ containing at most one point from each horizontal and vertical section whose boundary is $[0,1]\times[0,1]$
64920
Boundary Question in $\mathbb{R}^{2}$ (Manifolds)
3023
Construction of a Borel set with positive but not full measure in each interval
86902
Consider the smallest number in each of the $n\choose r$ subsets (of size $r$) of $S=\{1,2,\ldots,n\}$...
146204
Subsets sharing at most $i$ elements
81928
Covering with most possible equal size subsets having pairwise singleton intersections
14048
Proof that the complement of zero-measure set on $[0,1]$ is dense in $[0,1]$
144731
Disjoint closed sets in a second countable zero-dimensional space can be separated by a clopen set
6793
A linearly independent set about approximate units
143586
Is $[0,1]$ a union of family of disjoint closed intervals?
70266
1-1 correspondence between [0,1] and [0,1)
49374
Closure of a subset in a metric space
155004
Maximal points on an $n$-dimensional ellipsoid
127678
A partition of the unit interval into uncountably many dense uncountable subsets
151719
Connected set in $\mathbb{S}^1$
1409
Proving that the given set has at most $2^{n-1}$ elements
117658
A set with n elements has 2^n subsets
45485
Dimension of a subset