The future of the orbit of a point is a closed set
128482
The set of subsequential limits is closed
74792
$(X,\tau)$ needs to be $T_1$ in order to guarantee that $A'$ is closed?
8414
Proof verification: Set of partial limits of a sequence is closed
99678
Is a sphere a closed set?
144731
Disjoint closed sets in a second countable zero-dimensional space can be separated by a clopen set
121095
Is convex hull of a finite set of points in $\mathbb R^2$ closed?
127173
Closed subset of compact set is compact
91682
Graph of a continuous function is closed
113915
A star shaped open set in $\mathbb{R}^n$ is diffeomorphic to $\mathbb{R}^n$
105445
Are the rationals a closed or open set in $\mathbb{R}$?
44704
familly of Radially open sets in $\mathbb{R}^2$
97373
Is whether a set is closed or not a local property?
49374
Closure of a subset in a metric space
106944
Is the set defined by y=sin(1/x) open or closed?
43248
Closure of a Ball is Contained in Closed Ball (usual metric)
49703
Analogue of closed graph theorem
39416
The space obtained by identifying the antipodal points of a circle