Section round_dir_sign.
Variable rnd : R -> Z.
Context { valid_rnd : Valid_rnd rnd }.
Variable choice : bool -> Z -> location -> Z.
Hypothesis inbetween_int_valid :
forall x m l,
inbetween_int m (Rabs x) l ->
rnd x = cond_Zopp (Rlt_bool x 0) (choice (Rlt_bool x 0) m l).

Theorem round_sign_any_correct :
forall x m e l,
inbetween_float beta m e (Rabs x) l ->
(e = cexp beta fexp x \/ (l = loc_Exact /\ format x)) ->
round beta fexp rnd x = F2R (Float beta (cond_Zopp (Rlt_bool x 0) (choice (Rlt_bool x 0) m l)) e).