Jan Łukasiewicz (Polish pronunciation: [ˈjan wukaˈɕɛvʲitʂ]) (21 December 1878 – 13 February 1956) was a Polish logician and philosopher born in Lwów, Galicia, AustriaHungary (now Lviv, Ukraine). His work centred on analytical philosophy and mathematical logic. He thought innovatively about traditional propositional logic, the principle of noncontradiction and the law of excluded middle.
Contents 
A number of axiomatizations of classical propositional logic are owed to Łukasiewicz. A particularly elegant axiomatization features a mere three axioms and is still invoked down to the present day. He was a pioneer investigator of multivalued logics; his threevalued propositional calculus, introduced in 1917, was the first explicitly axiomatized nonclassical logical calculus. He wrote on the philosophy of science, and his approach to the making of scientific theories was similar to the thinking of Karl Popper.
Łukasiewicz invented the Polish notation (named after his nationality) for the logical connectives around 1920. This notation is the root of the idea of the recursive stack, a lastin, firstout computer memory store proposed by several researchers including Turing, Bauer and Hamblin, and first implemented in 1957. This design led to the English Electric multiprogrammed KDF9 computer system of 1963, which had two such hardware register stacks. A similar concept underlies the reverse Polish notation (RPN, a postfix notation) of the Friden EC130 calculator and its successors, many Hewlett Packard calculators, the Forth programming language, or the PostScript page description language.
At the beginning of World War II he worked at the secret Warsaw Underground University (Tajny Uniwersytet Warszawski). However at the end of the war he found refuge in Nazi Germany, in the village of Hembsen, where he was brought for his own safety due to accusations of collaboration with the Germans. Following the war he emigrated to Ireland and worked at the University of Dublin until his death.
In 2008 the Polish Information Processing Society established the Jan Łukasiewicz Award, to be presented to the most innovative Polish IT companies.^{[1]}
Cite error: There are <ref>
tags on this page, but the references will not show without a <references/>
tag.
