Extension

Extension, extend or extended may refer to:

Mathematics

Logic or set theory

• Axiom of extensionality
• Extensible cardinal
• Extension (model 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 by definitions
• Extensional definition, a definition that enumerates every individual a term applies to
• Extensionality

Other uses

• Extension of a polyhedron, in geometry
• Exterior algebra, Grassmann's theory of extension, in geometry
• 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), 1965
• Extensions, a 1969 album by Mystic Moods Orchestra
• Extensions (McCoy Tyner album), 1970
• Extensions (Dave Holland album), 1988
• Extensions (The Manhattan Transfer album), 1979

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), denoting movement of limb away from body, opposite of flexion
• Extension locus, the gene locus of Melanocortin 1 receptor

Other uses

• Continuing education, or extension school, a school for continuing education
• Cooperative extension service, a division of US Department of Agriculture
• 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
• Extension, the building of community capacity by outsiders, for instance agricultural extension
• Filename extension, for computer File systems