Editing Reciprocity

{{wiktionary|reciprocity}}
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'''Reciprocity''' may refer to:

==Law and trade==
* [[Reciprocity (Canadian politics)]], free trade with the United States of America
** [[Reciprocal trade agreement]], entered into in order to reduce (or eliminate) tariffs, quotas and other trade restrictions on items traded between the signatories
* Interstate reciprocity, recognition of sibling federated states' laws: 
** In the United States specifically: 
*** [[Full Faith and Credit Clause]], which provides for it
*** [[Concealed_carry_in_the_United_States#Reciprocity|Concealed carry reciprocity]]
** [[Occupational licensing]], which in some jurisdictions provides for it
* [[Traffic violations reciprocity]] where non-resident drivers are treated like residents
* [[Quid pro quo#Common law|Quid pro quo]], a legal concept of the exchange of good or services, each having value

==Social sciences and humanities==
* [[Norm of reciprocity]], social norm of in-kind responses to the behavior of others
* [[Reciprocity (cultural anthropology)]], way of defining people's informal exchange of goods and labour
* [[Reciprocity (evolution)]], mechanisms for the evolution of cooperation
* [[Reciprocity (international relations)]], principle that favours, benefits, or penalties that are granted by one state to the citizens or legal entities of another, should be returned in kind
* [[Reciprocity (social and political philosophy)]], concept of reciprocity as in-kind positive or negative responses for the actions of others
* [[Reciprocity (social psychology)]], in-kind positively or negatively connoted responses of individuals towards the actions of others
* Ethic of reciprocity (the [[Golden Rule]]), that one should treat others as one would like others to treat oneself
* [[Serial reciprocity]], in which the benefactor of a gift or service will in turn provide benefits to a third party

==Physical sciences and engineering==
* [[Reciprocity (engineering)]], used in the analysis of structures and to resolve complex load conditions
* [[Reciprocity (electromagnetism)]], theorems relating sources and the resulting fields in classical electromagnetism
* [[Reciprocity (electrical networks)]], reciprocity theorem as it relates to current and voltage in electrical networks
* [[Reciprocity (network science)]], measures the tendency of vertex pairs to form mutual connections between each other
* [[Reciprocity (optoelectronic)]],  a diode under illumination to the photon emission of the same diode under applied voltage
* [[Reciprocity (photography)]], the relationship between the intensity of the light and duration of the exposure that result in identical exposure
* [[Screw theory#Reciprocity of twist and wrench|Reciprocity of twist and wrench]], in screw theory
* [[Reciprocity theorem (disambiguation)]], several unrelated results
* Reciprocity of [[Antenna (radio)#Reciprocity|antenna]] transmitting and receiving characteristics
* [[Helmholtz reciprocity]], linear propagation.

==Mathematics==
* [[Reciprocity law]] (law of reciprocity) in mathematics, including
** [[Quadratic reciprocity]], a fundamental result in number theory
** [[Cubic reciprocity]], theorems that state conditions under which the congruence {{nowrap|''x''<sup>3</sup> ≡ ''p'' (mod ''q'')}} is solvable
** [[Quartic reciprocity]], a collection of theorems in elementary and algebraic number theory that state conditions under which the congruence {{nowrap|''x''<sup>4</sup> ≡ ''p'' (mod ''q'')}} is solvable
** [[Artin reciprocity law]], a general theorem in number theory that provided a partial solution to Hilbert's ninth problem
** [[Reciprocity relation]] or ''exact differential'', a mathematical differential of the form ''dQ'', for some differentiable function ''Q''
* [[Weil reciprocity law]]
* [[Mathematics of CRC#Reciprocal polynomials|Reciprocal polynomials]], the coefficients of the remainder polynomial are the bits of the CRC
* [[Reciprocal square root#Iterative methods for reciprocal square roots|Reciprocal square root]]
* [[Reciprocity (projective geometry)]], a collineation from a projective space onto its dual space, taking points to hyperplanes (and vice versa) and preserving incidence
* [[Frobenius reciprocity]], from group representation theory
* Reciprocity law for [[Dedekind sums]]
* [[Stanley's reciprocity theorem]], states that a certain functional equation is satisfied by the generating function of any rational cone and the generating function of the cone's interior
* [[Hermite reciprocity]] for invariants of binary forms.

==Other==
* [[Reciprocity (Fringe)|Reciprocity (''Fringe'')]], a 2011 episode of the television series ''Fringe''
* [[Rural Municipality of Reciprocity No. 32]], Saskatchewan, Canada
* "Reciprocity", a song by Loudon Wainwright III from his 1976 album ''[[T Shirt (album)|T Shirt]]''

==See also==
* [[Reciprocal (disambiguation)]]
* [[Reciprocation (disambiguation)]]
* [[Reciprocity Treaty (disambiguation)]]
* [[Reciprocal altruism]] between individuals of different species
* [[Meeting of the minds]] in contract law, sometimes called reciprocity
* [[Tit for tat]]
{{Mathematical disambiguation}}