Instance share_cross_split : Cross_alg t.

(* Specifications: *)
Lemma bot_correct' : forall x, join_sub bot x.
Lemma top_share_nonidentity : nonidentity top.
Lemma top_share_nonunit: nonunit top.
Lemma bot_join_eq : forall x, join bot x x.
Lemma join_bot_eq : forall x, join x bot x.
Lemma bot_joins : forall x, joins bot x.
Lemma dec_share_identity : forall x:t, { identity x } + { ~identity x }.
Lemma dec_share_nonunit : forall x:t, { nonunit x } + { ~ nonunit x }.
Lemma fullshare_full : full fullshare.
Lemma join_sub_fullshare : forall sh,
join_sub fullshare sh -> sh = fullshare.
Lemma dec_share_full : forall (sh : Share.t),
{full sh} + {~full sh}.