Section Double_round_plus_FLT.
Variable emin prec : Z.
Variable emin' prec' : Z.
Context { prec_gt_0_ : Prec_gt_0 prec }.
Context { prec_gt_0_' : Prec_gt_0 prec' }.

Theorem round_round_minus_FLT :
forall choice1 choice2,
(emin' <= emin)%Z -> (2 * prec + 1 <= prec')%Z ->
forall x y,
FLT_format beta emin prec x -> FLT_format beta emin prec y ->
round_round_eq (FLT_exp emin prec) (FLT_exp emin' prec')
choice1 choice2 (x - y).