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Diffstat (limited to 'theories/QArith/Qabs.v')
| -rw-r--r-- | theories/QArith/Qabs.v | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/theories/QArith/Qabs.v b/theories/QArith/Qabs.v index 116aa0d42..ec2ac7832 100644 --- a/theories/QArith/Qabs.v +++ b/theories/QArith/Qabs.v @@ -100,6 +100,13 @@ rewrite Z.abs_mul. reflexivity. Qed. +Lemma Qabs_Qinv : forall q, Qabs (/ q) == / (Qabs q). +Proof. + intros [n d]; simpl. + unfold Qinv. + case_eq n; intros; simpl in *; apply Qeq_refl. +Qed. + Lemma Qabs_Qminus x y: Qabs (x - y) = Qabs (y - x). Proof. unfold Qminus, Qopp. simpl. |