Section GeneralLseg.
Variable listrep: share -> list int -> val -> mpred.
Definition lseg (sh: share) (contents: list int) (x z: val) : mpred :=
ALL tcontents: list int, listrep sh tcontents z -* listrep sh (contents ++ tcontents) x.

Lemma list_lseg_proof_by_tactic: forall sh (s1 s2: list int) (x y: val),
listrep sh s2 y * lseg sh s1 x y |-- listrep sh (s1 ++ s2) x.