Heinrich Tietze
was born 137 years ago
31st August 1880

Heinrich Tietze was an Austrian mathematician, known for the Tietze extension theorem. He also developed the Tietze transformations for group presentations, and was the first to pose the group isomorphism problem.

Find out more at:
http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Tietze.html