(*The name is legacy. Comes from the time there was two shares. Then
 * The contradiction would look like 
 * forall (sh2 sh3:pshares) -> join pfullshare sh2 sh3 -> False. *)
Local Ltac pfulltac := try solve [exfalso; eapply join_writable0_readable; eauto].

Lemma readable_part_writable0: forall sh (Hw : writable0_share sh) (Hr : readable_share sh), readable_part (Hr) = exist _ _ pure_readable_Rsh.