reserve V for non empty RLSStruct;
reserve x,y,y1 for set;
reserve v for VECTOR of V;
reserve a,b for Real;

theorem Th6:
  for V being add-associative right_zeroed right_complementable
non empty addLoopStr, v,w being Element of V holds v + w = 0.V implies v = - w
proof
  let V be add-associative right_zeroed right_complementable non empty
  addLoopStr;
  let v,w be Element of V;
  assume v + w = 0.V;
  then w + v = 0.V by Lm1;
  hence thesis by Def10;
end;
