let prob_uwv ?(u = "") ?(v = "") w =
    (* Remplacer la ligne suivante par votre code *)
    match u,v,w with
    | (u,w,v) when u = "" && v = "" -> (float_of_int(H.find wf w) +. 1.) /. (float_of_int(_N +_V))
    | (u,w,v) when v = "" -> float_of_int(H.find wpf (u,w) + 1) /. (float_of_int(H.find wf u) +. float_of_int(_V))
    | (u,w,v) when u = "" -> (float_of_int(H.find wf w + 1) /. float_of_int(_N +_V)) *. (float_of_int(H.find wpf (w,v) + 1) /. ((float_of_int(H.find wf w) +. float_of_int(_V))))
    | (u,w,v) -> (float_of_int(H.find wpf (u,w) + 1) /. (float_of_int(H.find wf u) +. float_of_int(_V))) *. (float_of_int(H.find wpf (w,v) + 1) /. ((float_of_int(H.find wf w) +. float_of_int(_V))))