theorem Th11:
  for V being Abelian add-associative right_zeroed
  right_complementable non empty CLSStruct holds Sum(ZeroCLC V) = 0.V
proof
  let V be Abelian add-associative right_zeroed right_complementable non empty
  CLSStruct;
  consider F being FinSequence of the carrier of V such that
  F is one-to-one and
A1: rng F = Carrier (ZeroCLC V) and
A2: Sum(ZeroCLC V) = Sum(ZeroCLC V (#) F) by Def6;
  F = {} by A1,RELAT_1:41;
  then len(ZeroCLC V (#) F) = 0 by Def5,CARD_1:27;
  hence thesis by A2,RLVECT_1:75;
end;
