theorem Th11:
  for f being FinSequence of TOP-REAL 2, p being Point of TOP-REAL
  2 st len f >= 2 holds Index(f/.1,f) = 1
proof
  let f be FinSequence of TOP-REAL 2, p be Point of TOP-REAL 2;
  assume len f >= 2;
  then len f >= 1+1;
  then f/.1 in LSeg(f,1) by TOPREAL1:21;
  hence thesis by Th10;
end;
