Killing 1888 + Cartan 1894: complex simple Lie algebras = 4 classical (A_n B_n C_n D_n) + 5 exceptional (G_2 F_4 E_6 E_7 E_8); Dynkin diagrams encode root systems.
Killing 1888 + Cartan 1894: complex simple Lie algebras = 4 classical (A_n B_n C_n D_n) + 5 exceptional (G_2 F_4 E_6 E_7 E_8); Dynkin diagrams encode root systems.