INTERFACE Euclid;

CONST
  A = 0;
  B = 1;
  C = 2;
  D = 3;
  E = 4;
  F = 5;
  G = 6;
  H = 7;
  K = 8;
  L = 9;

  X = 10;

TYPE
  Id = INTEGER;

END Euclid.