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 :::Th42: :: AFF_1:28
  q1 in Line(p1,p2) & q2 in Line(p1,p2) & q1<>q2 implies Line(p1,
  p2) c= Line(q1,q2) by RLTOPSP1:75;
