Jan Łukasiewicz

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Jan Łukasiewicz (pronounced [ˈjan wukaˈɕɛvʲitʂ]) (21 December, 1878 – 13 February, 1956) was a Polish mathematician born in Lemberg, Galicia, Austria-Hungary (now Lviv, Ukraine). His major mathematical work centred on mathematical logic. He thought innovatively about traditional propositional logic, the principle of non-contradiction and the law of excluded middle.

1 Life and work
2 Chronology
3 See also
4 Further reading
5 External links

Life and work

To Łukasiewicz we owe a number of axiomatizations of classical propositional logic. A particularly elegant axiomatization features a mere three axioms and is still invoked down to the present day. He was a pioneer investigator of multi-valued logics; his three-valued propositional calculus, introduced in 1917, was the first explicitly axiomatized non-classical logical calculus. He wrote on the philosophy of science. 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 last-in, first-out computer memory store invented by Charles Hamblin [1] of the New South Wales University of Technology (NSWUT), and first implemented in 1957. This design led to the English Electric multi-programmed 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 EC-130 calculator and its successors, many Hewlett Packard calculators, the Forth programming language, or the PostScript page description language.

Łukasiewicz was a devout Roman Catholic.

Chronology

1878 Born
1890-1902 Studies with Kazimierz Twardowski in Lemberg (Lwów, L'viv)
1902 Doctorate (mathematics and philosophy), University of Lemberg with the highest distinction possible
1906 Habilitation thesis completed, University of Lemberg (Lwów, L'viv)
1906 Becomes a lecturer
1910 essays on the principle of non-contradiction and the excluded middle
1911 extraordinary professor at Lemberg (Lwów, L'viv)
1915 invited to the newly reopened University of Warsaw
1916 new Kingdom of Poland declared
1917 Develops three-valued propositional calculus
1919 Polish Minister of Education
1920-1939 professor at Warsaw University founds with Stanisław Leśniewski the Lwów-Warsaw School of logic (see also Alfred Tarski, Stefan Banach, Hugo Steinhaus, Zygmunt Janiszewski, Stefan Mazurkiewicz)
1928 marries Regina Barwińska
1946 exile in Belgium
1946 offered a chair by the University College Dublin
1953 writes autobiography
1956 Dies in Dublin