End RETADDR_EXISTS.
Remark code_tail_no_bigger:
forall pos c1 c2, code_tail pos c1 c2 -> (length c2 <= length c1)%nat.
Remark code_tail_unique:
forall fn c pos pos',
code_tail pos fn c -> code_tail pos' fn c -> pos = pos'.

Lemma return_address_offset_correct:
forall ge b ofs fb f c tf tc ofs',
transl_code_at_pc ge (Vptr b ofs) fb f c false tf tc ->
return_address_offset f c ofs' ->
ofs' = ofs.