Ltac joins_sh_contradiction_onside:=
match goal with
| [ H: joins ?sh1 ?sh2,
W1: writable0_share ?sh1,
W2: writable0_share ?sh2 |- _ ] =>
exfalso; eapply writable0_not_join_writable0; eassumption
| [ H: joins ?sh1 ?sh2,
W1: writable0_share ?sh1,
W2: readable_share ?sh2 |- _ ] =>
exfalso; eapply writable0_not_join_readable; eassumption
| [ H: joins Share.top ?sh2,
H0: ?sh2 <> Share.bot |- _ ] =>
exfalso; eapply H0; eapply only_bot_joins_top; eassumption
end.
Ltac joins_sh_contradiction:=
first[ joins_sh_contradiction_onside |
match goal with
| [ H: joins ?sh1 ?sh2 |- _ ] =>
eapply joins_comm in H
end; joins_sh_contradiction_onside].

(*HERE*)
Lemma joins_permDisjoint: forall r1 r2,
joins r1 r2 ->
permDisjoint (perm_of_res r1) (perm_of_res r2).