Example image of eyePlorer eyePlorer map for 'Interior (topology)': Mathematics Boundary (topology) Complement (set theory) Subset Topological space Topology Closure (topology) Duality (mathematics) Category theory Dual (category theory) If and only if Open set Idempotence Real number Rational number Complex number Finite set Lower limit topology Discrete space Trivial topology Kuratowski closure axioms Convex body Isolating neighborhood Relative interior Dense set Nowhere dense set Baire space Busemann's theorem Circle Compactly embedded Hyperconnected space Improper integral Neighbourhood (mathematics) Pickover stalk Semi-differentiability Carathéodory's theorem (conformal mapping) End (topology) Filled Julia set Kuratowski's closure-complement problem Mergelyan's theorem Cauchy's integral formula Zeta function universality Excision theorem Open mapping theorem (complex analysis) Banach–Tarski paradox Ehrhart polynomial Meagre set Star domain Dynkin's formula Gronwall's inequality