reserve r1,r2 for Real;
reserve n,i,i1,i2,j for Nat;
reserve D for non empty set;
reserve f for FinSequence of D;

theorem Th3:
  for p1,p2,q1,q2 being Point of TOP-REAL 2 st (p1`1 = p2`1 or p1
  `2 = p2`2)& LSeg(q1,q2) c= LSeg(p1,p2) holds q1`1 = q2`1 or q1`2 = q2`2
proof
  let p1,p2,q1,q2 be Point of TOP-REAL 2;
A1: q2 in LSeg(q1,q2) by RLTOPSP1:68;
  q1 in LSeg(q1,q2) by RLTOPSP1:68;
  hence thesis by A1,Th2;
end;
