Extension, extend or extended may refer to:
Mathematics
Logic or set theory
*
Axiom of extensionality
*
Extensible cardinal In mathematics, extendible cardinals are large cardinals introduced by , who was partly motivated by reflection principles. Intuitively, such a cardinal represents a point beyond which initial pieces of the universe of sets start to look simila ...
*
Extension (model theory)
In mathematical logic, an (induced) substructure or (induced) subalgebra is a structure whose domain is a subset of that of a bigger structure, and whose functions and relations are restricted to the substructure's domain. Some examples of subal ...
*
Extension (predicate logic), the set of tuples of values that satisfy the predicate
*
Extension (semantics)
In any of several fields of study that treat the use of signs — for example, in linguistics, logic, mathematics, semantics, semiotics, and philosophy of language — the extension of a concept, idea, or sign consists of the things to which i ...
, the set of things to which a property applies
*
Extension by definitions
*
Extensional definition
In logic, extensional and intensional definitions are two key ways in which the objects, concepts, or referents a term refers to can be defined. They give meaning or denotation to a term.
Intensional definition
An intensional definition gives ...
, 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, a branch of mathematics, a linear extension of a partial order is a total order (or linear order) that is compatible with the partial order. As a classic example, the lexicographic order of totally ordered sets is a linear ext ...
, in order theory
*
Sheaf extension, in algebraic geometry
*
Tietze extension theorem, in topology
*
Whitney extension theorem, in differential geometry
*
Group extension, in abstract algebra and homological algebra
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), a movement at a
joint
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...
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
*
Browser extension, a small software module for customizing a web browser
*
Building extension
*
Continuing education
Continuing education (similar to further education in the United Kingdom and Ireland) is an all-encompassing term within a broad list of post-secondary learning activities and programs. The term is used mainly in the United States and Canada.
...
, 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
A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically ...
, for computer file systems
See also
*
Extensive (disambiguation)
Extensive may refer to:
* Extensive property
* Extensive function
* Extensional In any of several fields of study that treat the use of signs — for example, in linguistics
Linguistics is the science, scientific study of human language. ...
{{Disambiguation