aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/Util/QUtil.v12
1 files changed, 12 insertions, 0 deletions
diff --git a/src/Util/QUtil.v b/src/Util/QUtil.v
index a3f4b1d00..71fdedeea 100644
--- a/src/Util/QUtil.v
+++ b/src/Util/QUtil.v
@@ -111,4 +111,16 @@ Section pow_ceil_mul_nat2.
eapply Qfloor_resp_le.
all: trivial; try omega; (eapply (Qle_trans _ 1 _); [vm_decide|assumption]).
Qed.
+
+ Lemma pow_ceil_mul_nat_divide_upperbound i :
+ wt (S i) / (wt i) <= b^Qceiling f.
+ Proof.
+ rewrite pow_ceil_mul_S.
+ rewrite Z_div_mult_full; [|apply pow_ceil_mul_nat_nonzero].
+ all:[ > | omega | eapply (Qle_trans _ 1 _); [vm_decide|assumption].. ].
+ apply Z.pow_le_mono_r; [ assumption | ].
+ rewrite Z.le_sub_le_add_l, Z.add_comm.
+ etransitivity; [ | apply Qceiling_le_add ].
+ reflexivity.
+ Qed.
End pow_ceil_mul_nat2.