diff --git a/hw1/bin/hellocaml.ml b/hw1/bin/hellocaml.ml
index b2de40a..1687cca 100644
--- a/hw1/bin/hellocaml.ml
+++ b/hw1/bin/hellocaml.ml
@@ -742,7 +742,12 @@ let rev_t (l : 'a list) : 'a list =
   evaluates to true or false.
 *)
 let rec insert (x : 'a) (l : 'a list) : 'a list =
-  failwith "insert unimplemented"
+  match l with
+  | [] -> [x]
+  | h :: hs ->
+      if x < h then x :: l
+      else if x = h then l
+      else h :: insert x hs
 
 (*
   Problem 3-6
@@ -752,7 +757,10 @@ let rec insert (x : 'a) (l : 'a list) : 'a list =
   Hint: you might want to use the insert function that you just defined.
 *)
 let rec union (l1 : 'a list) (l2 : 'a list) : 'a list =
-   failwith "union unimplemented"
+  (* Ideally you'd insert the smallest list into the larger one, but I'll go with the simplest implementation here *)
+  match l1 with
+  | [] -> l2
+  | x :: xs -> union xs (insert x l2)
 
 (******************************************************************************)
 (*                                                                            *)