Jean-Pierre Sydler (1921-1988) was a Swiss mathematician and a librarian, well known for his work in geometry, most notably on Hilbert's third problem.
He graduated from ETH Zürich in 1943 and received a doctorate in 1947.
In 1950 he became a librarian at the ETH while continuing to publish mathematical papers in his spare time.
In 1960 he received a prize of the Danish Academy of Sciences for his work on scissors congruence.
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