Section Fprop_plus_le_ops.
Variable beta : radix.
Variable fexp : Z -> Z.
Context { valid_exp : Valid_exp fexp }.
Variable choice : Z -> bool.

Lemma plus_error_le_l :
forall x y,
generic_format beta fexp x -> generic_format beta fexp y ->
(Rabs (round beta fexp (Znearest choice) (x + y) - (x + y)) <= Rabs x)%R.