Definition same_except_cur (m m' : Mem.mem) :=
Mem.mem_contents m = Mem.mem_contents m' /\
max_access_at m = max_access_at m' /\
Mem.nextblock m = Mem.nextblock m'.

Lemma weak_exclusive_joins_false R phi phi1 phi2 :
level phi = level phi1 ->
app_pred (weak_exclusive_mpred R) phi ->
app_pred R phi1 ->
app_pred R phi2 ->
joins phi1 phi2 ->
False.