Remark in_remove:
forall (A: Type) (eq: forall (x y: A), {x=y}+{x<>y}) x y l,
In y (List.remove eq x l) <-> x <> y /\ In y l.

Lemma add_load_holds:
forall valu1 ge sp rs m n addr (args: list reg) a chunk v dst,
numbering_holds valu1 ge sp rs m n ->
eval_addressing ge sp addr rs##args = Some a ->
Mem.loadv chunk m a = Some v ->
exists valu2, numbering_holds valu2 ge sp (rs#dst <- v) m (add_load n dst chunk addr args).