(** [Loc.norepet ll] holds if the locations in list [ll] are pairwise different. *)
Inductive norepet : list loc -> Prop :=
| norepet_nil:
norepet nil
| norepet_cons:
forall hd tl, notin hd tl -> norepet tl -> norepet (hd :: tl).

Lemma gus: forall ll l m, In l ll -> (undef ll m) l = Vundef.
Definition getpair (p: rpair loc) (m: t) : val :=
match p with
| One l => m l
| Twolong l1 l2 => Val.longofwords (m l1) (m l2)
end.