Extension

Extension, extend or extended may refer to:

Mathematics

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

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

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

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

Agricultural Extension
Browser extension, a small software module for customizing a web browser
Building extension
Continuing education, or extension school, a school for continuing education
Cooperative State Research, Education, and Extension Service, a former division of the U.S. 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