Conformal, Integrable and Topological Theories, Graphs and Coxeter   Groups
  I review three different problems occuring in two dimensional field theory: 1) classification of conformal field theories; 2) construction of lattice integrable realizations of the latter; 3) solutions to the WDVV equations of topological field theories. I show that a structure of Coxeter group is hidden behind these three related problems. 
J.-B. Zuber