let qq =
  let rec qx x y = 
    let rec qy x y = 
      if y > 9 then qx x 1 else (Printf.printf "%dx%d=%d\n" x y (x * y); qy x (y + 1))
    in
    if x >= 9 then () else qy (x + 1) y
  in
  qx 0 1

let () = qq