reserve            S for satisfying_CongruenceSymmetry
                         satisfying_CongruenceEquivalenceRelation
                         TarskiGeometryStruct,
         a,b,c,d,e,f for POINT of S;
reserve S for satisfying_CongruenceSymmetry
              satisfying_CongruenceEquivalenceRelation
              satisfying_CongruenceIdentity
              satisfying_SegmentConstruction
              satisfying_SAS
              TarskiGeometryStruct,
        q,a,b,c,a9,b9,c9,x1,x2 for POINT of S;
reserve S for satisfying_CongruenceIdentity
              satisfying_SegmentConstruction
              satisfying_BetweennessIdentity
              satisfying_Pasch
              TarskiGeometryStruct,
        a,b,c,d for POINT of S;

theorem Satz3p2:
  between a,b,c implies between c,b,a
  proof
    assume
A1: between a,b,c;
    between b,c,c by Satz3p1;
    then ex x be POINT of S st between b,x,b & between c,x,a
      by A1,GTARSKI1:def 11;
    hence thesis by GTARSKI1:def 10;
  end;
