theorem
  for S being trivial (IE) (SC) non empty TarskiGeometryStruct holds S is (RE)
  proof
    let S be trivial (IE) (SC) non empty TarskiGeometryStruct;
    let a,b be POINT of S;
    a = b by ZFMISC_1:def 10;
    hence thesis by Satz2p8;
  end;
