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.