 reserve n for Nat;

theorem ThConv7ter:
  for a,b being Point of TarskiEuclid2Space st between a,b,a holds a = b
  proof
    let a,b be Point of TarskiEuclid2Space;
    assume between a,b,a;
    then Tn2TR b in LSeg(Tn2TR a,Tn2TR a) by ThConv6;
    then Tn2TR b in { Tn2TR a } by RLTOPSP1:70;
    hence thesis by TARSKI:def 1;
  end;
