reserve a,b,s,t,u,lambda for Real,
  n for Nat;
reserve x,x1,x2,x3,y1,y2 for Element of REAL n;
reserve p1,p2,q1,q2 for Point of TOP-REAL n;

theorem Th44: :: AFF_1:31
  for A being Subset of TOP-REAL n st A is being_line holds ex p1,
  p2 st p1 in A & p2 in A & p1<>p2
proof
  let A be Subset of TOP-REAL n;
  assume A is being_line;
  then consider p1,p2 such that
A1: p1<>p2 and
A2: A = Line(p1,p2);
  p1 in A & p2 in A by A2,RLTOPSP1:72;
  hence thesis by A1;
end;
