let rec unif_uplet_norm s = function
| Uplet(l)::fin -> unif_uplet_norm s (l@fin)
| (Var n)::fin ->
let t = valeur n s in
if t = (Var n) then t::(unif_uplet_norm s fin) else (unif_uplet_norm s (t::fin))
| (Xor _)::_ -> raise NeedXor
| t::fin -> t::(unif_uplet_norm s fin)
| [] -> []