(* field_offset2_in_range union's version *)

Lemma neq_field_offset_next_rec_cons: forall env i i0 t0 i1 t1 m z sz,
i <> i0 ->
field_offset_next_rec env i ((i0, t0) :: (i1, t1) :: m) z sz =
field_offset_next_rec env i ((i1, t1) :: m) (align (z +  sizeof t0) (alignof t1)) sz.