Example image of eyePlorer eyePlorer map for 'Singleton (mathematics)': Mathematics Set (mathematics) Uniqueness quantification Cardinality If and only if Set-theoretic definition of natural numbers Axiom of empty set Axiom of pairing Empty set Set theory Function (mathematics) Closed set T1 space Topology Category (mathematics) Category of sets Initial and terminal objects Topological space Group (mathematics) Identity element Group homomorphism Boolean-valued function Class (set theory) Dirac measure Subgame Trivial ring Characterization (mathematics) Conjugacy class Conjugate closure Separating set Sober space Unit type Axiom of infinity Binary set Generic point Monogenic semigroup State transition system Block (group theory) Category of metric spaces Category of preordered sets Conjugation of isometries in Euclidean space Grothendieck universe Tarski–Grothendieck set theory Trivial (mathematics) Category of magmas Cocountability Complete numbering Range query Regular language Group object