for i = 0 to pts.length - 1 do
   // Primo punto di controllo
   let mutable m1 = match single(pts.[i+1].Y - pts.[i].Y) with
    | 0.f -> 0.f
    | _ -> single(single(pts.[i+1].X - pts.[i].X)/single(pts.[i+1].Y - pts.[i].Y))