Beside the portrait of Stefan Banach on this 2012 coin there is no ornament but mathematics: the graph of a linear operator and an inequality. This is how the National Bank of Poland marked 120 years since the birth of a co-founder of the famous Polish School of Mathematics; the 2 zlote coin was issued on 3 April 2012.

The reverse was designed by Robert Kotowicz: a stylised bust of the scholar with the graph and inequality below, and the inscriptions «STEFAN BANACH» and «1892-1945». The obverse with the state eagle is by Ewa Tyc-Karpińska.

Banach was born in Kraków but made his name in Lwów, teaching at the Polytechnic and at Jan Kazimierz University. Banach spaces, the Hahn–Banach theorem and the Banach fixed-point theorem all bear his name.

The Scottish Café became a legend of interwar Lwów: Banach and his colleagues met there almost every day, recording problems and solutions in the famous Scottish Book. He died in August 1945.

The coin belongs in a scientists theme, a science-on-coins collection and a 2012 date run. UNC grade: never circulated, no wear, original mint lustre retained.

This coin is one of the items in the VPcoins catalogue, which brings together commemorative, circulation and bullion coins from around the world.