let rec mk_toffset_access expr base off =
(* same then [fol_offset_access] for fot logic terms *)
match off with
| TNoOffset -> base
| TField (f, next) ->
mk_toffset_access expr (fol_field_access base f) next
| TIndex (t,next) ->
mk_toffset_access expr (Why_ops.array_access base (expr t)) next