enrich
cell-heap,
list
with
functions ls : ref × list → heap → bool;
axioms ls-base : ⊦ ls(r, []) = (emp ∧ ⌜r = null⌝ );
used for: s, ls;
ls-rec : ⊦ ls(r, a ' + x) = _∃(λ r0. r => a × r0 * ls(r0, x));
used for: s, ls;
end enrich