theorem
  for v being object, G1 being addAdjVertexAll of G2,v,V
  holds G1.eChromaticNum() c= G2.eChromaticNum() +` card V
proof
  let v be object, G1 be addAdjVertexAll of G2,v,V;
  G2 is G2.eChromaticNum()-ecolorable by Lm14;
  hence thesis by Lm15;
end;
