The Erlanger program describes geometric structures in terms of their automorphism groups and was initiated by Klein (1872).
Erlanger Program
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References
Klein, F. "Vergleichende Betrachtungen über neuere geometrische Forschungen." 1872.Yaglom, I. M. Felix Klein and Sophus Lie: Evolution of the Idea of Symmetry in the Nineteenth Century. Boston, MA: Birkhäuser, 1988.Referenced on Wolfram|Alpha
Erlanger ProgramCite this as:
Weisstein, Eric W. "Erlanger Program." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ErlangerProgram.html