theorem
  for V being Abelian add-associative right_zeroed right_complementable
non empty CLSStruct, l being C_Linear_Combination of {}(the carrier of V) holds
  Sum l = 0.V
proof
  let V be Abelian add-associative right_zeroed right_complementable non empty
  CLSStruct;
  let l be C_Linear_Combination of {}(the carrier of V);
  l = ZeroCLC V by Th5;
  hence thesis by Th11;
end;
