reserve E for compact non vertical non horizontal Subset of TOP-REAL 2,
  C for compact connected non vertical non horizontal Subset of TOP-REAL 2,
  G for Go-board,
  i, j, m, n for Nat,
  p for Point of TOP-REAL 2;

theorem
  for p,q be Point of TOP-REAL 2 st p <> q & LSeg(p,q) is horizontal
  holds <*p,q*> is being_S-Seq
proof
  let p,q be Point of TOP-REAL 2;
  assume that
A1: p <> q and
A2: LSeg(p,q) is horizontal;
  p`2 = q`2 by A2,SPPOL_1:15;
  hence thesis by A1,SPPOL_2:43;
end;
