theorem Th75:
  ==>.-relation(TS) reduces [x, v], [y, w] implies len v >= len w
proof
  assume ==>.-relation(TS) reduces [x, v], [y, w];
  then
  ex P being RedSequence of ==>.-relation(TS) st P.1 = [x, v] & P.len P = [
  y, w] by REWRITE1:def 3;
  hence thesis by Th59;
end;
