Example image of eyePlorer eyePlorer map for 'Closed set': Complement (set theory) Mathematics Open set Set (mathematics) Topology Topological space Limit point Closed manifold Boundary (topology) Finite set Intersection (set theory) Union (set theory) Empty set Countable set Fσ set Interval Real number Rational number Unit interval Interval (mathematics) Clopen set General topology Differentiable manifold Metric space Uniform space Net (mathematics) Sequence First-countable space Limit of a sequence Compact space Hausdorff space Stone–Čech compactification Tychonoff space Arc (geometry) Banach–Alaoglu theorem Bernstein set Borel set Closed convex function Closed range theorem Club set Cone (linear algebra) Dense set Extreme value theorem Gδ space Identity component Invariant subspace problem Limits of integration Michael selection theorem Nilmanifold Paranormal space