Section RETADDR_EXISTS.
Hypothesis transl_instr_tail:
forall f i ep k c, transl_instr f i ep k = OK c -> is_tail k c.
Hypothesis transf_function_inv:
forall f tf, transf_function f = OK tf ->
exists tc, exists ep, transl_code f (Mach.fn_code f) ep = OK tc /\ is_tail tc (fn_code tf).
Hypothesis transf_function_len:
forall f tf, transf_function f = OK tf -> list_length_z (fn_code tf) <= Ptrofs.max_unsigned.

Lemma transl_code_tail:
forall f c1 c2, is_tail c1 c2 ->
forall tc2 ep2, transl_code f c2 ep2 = OK tc2 ->
exists tc1, exists ep1, transl_code f c1 ep1 = OK tc1 /\ is_tail tc1 tc2.