(* Corrigé du TP noté *)



(* 1 *)


let rec adjoint l ms = 
  match(ms) with
   [] -> []
  | m::ms -> (l::m)::(adjoint l ms);;


(* 2 *)


let rec filtre m1 m2 = 
    match(m1,m2) with
      ([],[])      -> true
    | (t1::r1,[])  -> false
    | ([],t2::r2)  -> false
    | (t1::r1,t2::r2) -> (t1=t2 or t2='?') & (filtre r1 r2);;


(* 3 *)


let rec extrait m n = 
    match(m) with
      []   -> [[]]
    | t::r -> if n=0 then [[]]
                     else let l1 = extrait r n in
                          let l2 = extrait r (n-1) in
                              l1 @ (adjoint t l2);;