Extension, extend or extended may refer to:

Mathematics

Logic or set theory

  • Axiom of extensionality
  • Extensible cardinal
  • Extension (model theory)
  • Extension (proof theory)
  • Extension (predicate logic), the set of tuples of values that satisfy the predicate
  • Extension (semantics), the set of things to which a property applies
  • Extension (simplicial set)
  • Extension by definitions
  • Extensional definition, a definition that enumerates every individual a term applies to
  • Extensionality

Other uses

  • Extension of a function, defined on a larger domain
  • Extension of a polyhedron, in geometry
  • Extension of a line segment (finite) into an infinite line (e.g., extended base)
  • Exterior algebra, Grassmann's theory of extension, in geometry
  • Field extension, in Galois theory
  • Group extension, in abstract algebra and homological algebra
  • Homotopy extension property, in topology
  • Kolmogorov extension theorem, in probability theory
  • Linear extension, in order theory
  • Sheaf extension, in algebraic geometry
  • Tietze extension theorem, in topology
  • Whitney extension theorem, in differential geometry

Music

  • Extension (music), notes that fit outside the standard range
  • Extended (Solar Fields album), 2005
  • Extension (George Braith album), 1964
  • Extension (Clare Fischer album), 1963
  • Extensions (Ahmad Jamal album), 1960
  • Extensions, a 1969 album by Mystic Moods Orchestra
  • Extensions (McCoy Tyner album), 1970
  • Extensions (Dave Holland album), 1988
  • Extensions (The Manhattan Transfer album), 1979
  • Extension (The Extended Mixes), 2023 album reissue by Kylie Minogue

Places

  • Extension, British Columbia, a village near Regional District of Nanaimo, British Columbia, Canada
  • Extension, Louisiana, unincorporated community, United States

Science

  • Extension (geology), relating to the pulling apart of the Earth's crust and lithosphere
  • Extension (anatomy), a movement at a joint that increases the angle between the two ends of the joint; the opposite of flexion
  • Extension locus, the gene locus of Melanocortin 1 receptor

Other uses

  • Agricultural extension service
  • Cooperative State Research, Education, and Extension Service, a former division of the U.S. Department of Agriculture
  • Extension, the building of community capacity by outsiders, for instance agricultural extension
  • Plug-in (computing), a software component that adds a specific feature to an existing computer program
  • Browser extension, a small software module for customizing a web browser
  • Building extension
  • Continuing education, or extension school, a school for continuing education
  • Extension (metaphysics), the property of stretching out or taking up space
  • Extension (telephone), telephone line attached to a main line or to a PBX or Centrex system
  • Extension cord, power cable with a plug on one end and one or more sockets on the other end
  • Eyelash extensions, material applied to eyelashes
  • Hair extensions, strands of hair added to existing hair
  • Filename extension, for computer file systems

See also

  • Extensive (disambiguation)