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 :::Th40: :: AFF_1:26
  p1 in Line(p1,p2) & p2 in Line(p1,p2) by RLTOPSP1:72;
