Difference between revisions 7623324 and 12959227 on enwiki

The '''Wigner - d'Espagnat inequality''' is a basic result of [[set theory]].
It is named for [[Eugene Wigner]] and Bertrand d'Espagnat who (as pointed out by [[John Stewart Bell|Bell]]) both employed it in their popularizations of [[quantum mechanics]].

Given a set S with three subsets, J, K, and L, the following holds:

* each member of S which is a member of J, but not of L 
:: is either a member of J, but neither of K, nor of L, 
(contracted; show full)

Similar interdependencies between ''two'' particular measurements and the corresponding operators are the [[uncertainty principle|uncertainty relations]] as first expressed by [[Werner Heisenberg|Heisenberg]] for the interdependence between measurements of distance and of momentum, and as generalized by [[Edward Condon]], [[Howard Percy Robertson]], and [[Erwin Schrödinger]].


====Reference====
* John S. Bell, ''Bertlmann's socks and the nature of reality'', Journal de Physique '''42''', no. 3, p. 41 (1981); and references therein.⏎
⏎
[[Category:Inequalities]]