View source for Biography:Jerzy Łoś

{{Infobox scientist
| name              = Jerzy Łoś
| image             = Jerzy Los c1955.jpg
| caption           = Jerzy Łoś c.1955
| birth_date        = {{birth date|1920|3|22|df=y}}
| birth_place       = Lvov, [[Place:Second Polish Republic|Second Polish Republic]]
| death_date        = {{death date and age|1998|6|1|1920|3|22|df=y}}
| death_place       = [[Place:Warsaw|Warsaw]], Third Polish Republic
| nationality       = Polish
| field             = {{flatlist|
* [[Mathematics]]
** [[Mathematical logic|Logic]]
** [[Finance:Mathematical economics|Economics]]
** [[Philosophy:Philosophy of mathematics|Philosophy]]
}}
| known_for         = Łoś's theorem<br>[[Łoś–Vaught test]]
| influences        = [[Biography:Hugo Steinhaus|Hugo Steinhaus]], Edward Marczewski
}}
'''Jerzy Łoś''' (born 22 March 1920 in Lwów, {{wipe|Poland}} (now Lviv, {{wipe|Ukraine}}) – 1 June 1998 in [[Place:Warsaw|Warsaw]]) ({{IPA-pol|ˈjɛʐɨ ˈwɔɕ}}) was a Polish [[Biography:Mathematician|mathematician]], logician, [[Social:Economist|economist]], and [[Biography:Philosopher|philosopher]]. He is especially known for his work in [[Model theory|model theory]], in particular for "[[Ultraproduct#.C5.81o.C5.9B.27 theorem|Łoś's theorem]]", which states that any first-order formula is true in an ultraproduct if and only if it is true in "most" factors (see [[Ultraproduct|ultraproduct]] for details). In model theory he also proved many preservation theorems, but he gave significant contributions, as well, to [[Philosophy:Foundations of mathematics|foundations of mathematics]], [[Abelian group|Abelian group theory]] and [[Universal algebra|universal algebra]]. In the 60's he turned his attention to [[Finance:Mathematical economics|mathematical economics]], focusing mainly on production processes and dynamic decision processes.

He was faculty at academies in Wrocław, Toruń, and [[Place:Warsaw|Warsaw]].

In 1996, Łoś suffered from a severe brain stroke. He was thenceforward ill until his death in 1998.

==Selected publications==

* Łoś, Jerzy (1955) Quelques remarques, théorèmes et problèmes sur les classes définissables d'algèbres.  Mathematical interpretation of formal systems, pp.&nbsp;98–113. North-Holland Publishing Co., Amsterdam.

==See also==

* {{annotated link|Hyperreal number}}
* {{annotated link|Łoś–Vaught test}}
* {{annotated link|Transfer principle}}

==External links==
* [http://www.ipipan.waw.pl/GTME2004/Los1.pdf Jerzy Łoś's biography]

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{{succession box | before=[[Biography:Patrick Suppes|Patrick Suppes]]| title=President of the DLMPST/IUHPST | years=1979&ndash;1983 | after=[[Biography:Dana Scott|Dana Scott]]}}
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[[Category:20th-century mathematicians]]


{{Sourceattribution|Jerzy Łoś|1}}