theorem
  AS is not AffinPlane implies AS is translational
proof
  assume AS is not AffinPlane;
  then
  for A,P,C,a,b,c,a9,b9,c9 holds A // P & A // C & a in A & a9 in A & b in
  P & b9 in P & c in C & c9 in C & A is being_line & P is being_line & C is
being_line & A<>P & A<>C & a,b // a9,b9 & a,c // a9,c9 implies b,c // b9,c9 by
Th51;
  hence thesis by AFF_2:def 11;
end;
