reserve n for Nat,
  i,j for Nat,
  r,s,r1,s1,r2,s2,r9,s9 for Real,
  p,q for Point of TOP-REAL 2,
  G for Go-board,
  x,y for set,
  v for Point of Euclid 2;

theorem
  LSeg(p,G*(1,width G)+|[-1,1]|) meets Int cell(G,0,width G)
proof
  now
    take a = G*(1,width G)+|[-1,1]|;
    thus a in LSeg(p,G*(1,width G)+|[-1,1]|) by RLTOPSP1:68;
    thus a in Int cell(G,0,width G) by Th38;
  end;
  hence thesis by XBOOLE_0:3;
end;
