(** or it wasn't and the operation denoted by the event implies the permission*)
(** *** Properties about permission decay and events *)

Lemma lockRes_permission_decrease_execution:
forall U tr tpi mi U' tpj mj tr' laddr rmapi rmapj b ofs
(Hres: lockRes tpi laddr = Some rmapi)
(Hres': lockRes tpj laddr = Some rmapj)
(Hexec: multi_step (U, tr, tpi) mi (U', tr ++ tr', tpj) mj)
(Hperm: (Mem.perm_order'' (rmapi.1 !! b ofs) (Some Readable) /\
~ Mem.perm_order'' (rmapj.1 !! b ofs) (Some Readable)) \/
(Mem.perm_order'' (rmapi.2 !! b ofs) (Some Readable) /\
~ Mem.perm_order'' (rmapj.2 !! b ofs) (Some Readable))),
exists v ev,
nth_error tr' v = Some ev /\ action ev = Acquire /\
location ev = Some (laddr, lksize.LKSIZE_nat).