Nikolai Aleksandrovich Shanin (russian: Николай Александрович Шанин) (25 May 1919

Pskov Pskov ( rus, Псков, a=pskov-ru.ogg, p=pskof; see also names in other languages) is a city in northwestern Russia and the administrative center of Pskov Oblast, located about east of the Estonian border, on the Velikaya River. Population ...

– 17 September 2011) was a Russian mathematician who worked on

topology In mathematics, topology (from the Greek language, Greek words , and ) is concerned with the properties of a mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformations, such ...

and

constructive mathematics In the philosophy of mathematics, constructivism asserts that it is necessary to find (or "construct") a specific example of a mathematical object in order to prove that an example exists. Contrastingly, in classical mathematics, one can prove th ...

. He introduced the

delta-system lemma In the mathematical fields of set theory and extremal combinatorics, a sunflower or \Delta-system is a collection of sets whose pairwise intersection is constant. This constant intersection is called the kernel of the sunflower. The main re ...

and the

caliber In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel Gauge (firearms) , bore – regardless of how or where the bore is measured and whether the f ...

of a topological space.

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Nikolai Aleksandrovich Shanin
at the Steklov Institute of Mathematics at St. Petersburg {{DEFAULTSORT:Shanin, Nikolai Aleksandrovich Russian mathematicians 1919 births 2011 deaths People from Pskov

Further reading

External links