diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32d2f14cd8c367fb5987ebe5a0e5d3f0993e2dcf..e82c2830a212c7319b1ae96b3b477973e0123231 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,7 +12,8 @@ API-breaking change is listed.
 - Rename `map_filter_empty_iff` to `map_empty_filter` and add
   `map_empty_filter_1` and `map_empty_filter_2`. (by Michael Sammler)
 - Add lemma about `zip_with`: `lookup_zip_with_None` and add lemmas for `zip`:
-  `length_zip`, `zip_nil_inv`, `lookup_zip_Some`,`lookup_zip_None`. (by Kimaya Bedarkar)
+ `length_zip`, `zip_nil_inv`, `lookup_zip_Some`,`lookup_zip_None`. (by Kimaya Bedarkar)
+- Add `elem_of_seq` and `seq_nil`. (by Kimaya Bedarkar)
 
 The following `sed` script should perform most of the renaming
 (on macOS, replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`).
diff --git a/stdpp/list_numbers.v b/stdpp/list_numbers.v
index 3333e22d01ccb3836d40556e8fcb09f336844ccb..4489e5a89e7876c5e870e3292adcdd0f2a9748ae 100644
--- a/stdpp/list_numbers.v
+++ b/stdpp/list_numbers.v
@@ -98,6 +98,12 @@ Section seq.
     k ∈ seq j n ↔ j ≤ k < j + n.
   Proof. rewrite elem_of_list_In, in_seq. done. Qed.
 
+  Lemma seq_nil n m : seq n m = [] ↔ m = 0.
+  Proof. by destruct m. Qed.
+
+  Lemma seq_subseteq_mono m n1 n2 : n1 ≤ n2 → seq m n1 ⊆ seq m n2.
+  Proof. by intros Hle i Hi%elem_of_seq; apply elem_of_seq; lia. Qed.
+
   Lemma Forall_seq (P : nat → Prop) i n :
     Forall P (seq i n) ↔ ∀ j, i ≤ j < i + n → P j.
   Proof. rewrite Forall_forall. setoid_rewrite elem_of_seq. auto with lia. Qed.
@@ -118,6 +124,7 @@ Section seq.
     - rewrite take_nil. replace (m `min` 0) with 0 by lia. done.
     - destruct m; simpl; auto with f_equal.
   Qed.
+
 End seq.
 
 (** ** Properties of the [seqZ] function *)