Definition Lsh  : Share.t := fst (Share.split Share.top).
Definition Rsh  : Share.t := snd (Share.split Share.top).
Definition splice (a b: t) : t := Share.lub (rel Lsh a) (rel Rsh b).

Lemma contains_Rsh_e: forall sh,
join_sub Rsh sh ->
unrel Rsh sh = top.