Definition shr mrs e n :=
match n with
| Zpos p => (iter_pos shr_1 p mrs, (e + n)%Z)
| _ => (mrs, e)
end.

(* Specifications: *)
Lemma inbetween_shr_1 :
forall x mrs e,
(0 <= shr_m mrs)%Z ->
inbetween_float radix2 (shr_m mrs) e x (loc_of_shr_record mrs) ->
inbetween_float radix2 (shr_m (shr_1 mrs)) (e + 1) x (loc_of_shr_record (shr_1 mrs)).
Theorem inbetween_shr :
forall x m e l n,
(0 <= m)%Z ->
inbetween_float radix2 m e x l ->
let '(mrs, e') := shr (shr_record_of_loc m l) e n in
inbetween_float radix2 (shr_m mrs) e' x (loc_of_shr_record mrs).