reserve x,y,z for object,X,Y for set;
reserve N for e_net;

theorem Th2:
  G_Net (# X, {}, {} #) is e_net
proof
  {} c= [:X, X:] & {} * ({} \ id(X)) = {} by XBOOLE_1:2;
  hence thesis by Def1,Def2;
end;
