diff --git a/src/stdlib.cg b/src/stdlib.cg
index dd450c2..2efeb76 100644
--- a/src/stdlib.cg
+++ b/src/stdlib.cg
@@ -32,33 +32,77 @@ drop = n list \ { n = n, list = list }
   | { n = 0, list = _ } \ list
   | { n = _, list = [x, ...xs] } \ drop (n - 1) xs;
 
-# zipWith = (a \ b \ c) List a \ List b \ List c
+# zipWith : (a \ b \ c) \ List a \ List b \ List c
 zipWith = f l1 l2 \ l1
   | [] \ []
   | [x, ...xs] \ (l2
     | [] \ []
     | [y, ...ys] \ [f x y, ...zipWith f xs ys]);
 
+# contains : a \ List a | Bool
+contains = x list \ list
+  | [] \ False
+  | [y, ...ys] \ (x == y
+    | True \ True
+    | False \ contains x ys);
+
+# find : (a \ Bool) \ List a \ Maybe a
+find = f list \ list
+  | [] \ None
+  | [x, ...xs] \ (f x
+    | True \ Some x
+    | False \ find f xs);
+
+# flatten : List (List a) \ List a
+flatten = lists \ fold cat [] lists;
+
 # and : Bool \ Bool \ Bool
 and = x y \ x
   | False \ False
-  | True \ (y | False \ False | True \ True);
+  | True \ y;
 
 # or : Bool \ Bool \ Bool
 or = x y \ x
   | True \ True
-  | False \ (y | True \ True | False \ False);
+  | False \ y;
 
-# not = Bool \ Bool
+# not : Bool \ Bool
 not = x \ x
   | True \ False
   | False \ True;
 
-# isSome = maybe \ ...
-# isNone = maybe \ ...
-# unwrapOr = default maybe \ ...
+# isSome : Maybe a \ Bool
+isSome = a \ a
+  | Some _ \ True
+  | _ \ False;
+
+# isNone : Maybe a \ Bool
+isNone = a \ a
+  | Some _ \ False
+  | _ \ True;
+
+# unwrapOr : a \ Maybe a \ a
+unwrapOr = default x \ x
+  | Some val \ val
+  | _ \ default;
+
+# if : Bool \ a \ a \ a
+if = test a b \ test
+  | True \ a
+  | _ \ b;
+
+# range : Int \ Int \ List Int
+# [start, start+1, ..., end-1]
+range = start end \ start >= end
+  | True \ []
+  | False \ [start, ...range (start + 1) end];
+
+# sum : List Int \ Int
+# TODO sum floats too? wait for typeclasses?
+sum = list \ fold add 0 list;
+
+# any : (a \ Bool) \ List a \ Bool
+any = f list \ fold (acc x \ or acc (f x)) False list;
 
-# range = start end \ ... # [start, start+1, ..., end-1]
-# sum = list \ ...
-# any = f list \ ...
-# all = f list \ ...
+# all : (a \ Bool) \ List a \ Bool
+all = f list \ fold (acc x \ and acc (f x)) True list;
diff --git a/src/test.cg b/src/test.cg
index de67e0a..cc785f8 100644
--- a/src/test.cg
+++ b/src/test.cg
@@ -1,44 +1,43 @@
-list = [1, 2, 3, 4, 5];
+# standard library testing
 
+list = [1, 2, 3, 4, 5];
 add1 = x \ x + 1;
-
 mapped = map add1 list;
-
 isEven = x \ x % 2 == 0;
-
 sumList = list \ fold add 0 list;
-
 filtered = filter isEven mapped;
-
 summed = sumList mapped;
-
-l = len list;
-
+listLen = len list;
 reversed = reverse list;
-
 take3 = take 3 list;
-
 drop3 = drop 3 list;
-
 list2 = [6, 7, 8];
-
 zipped = zipWith add list list2;
-
 anded = and True False;
-
 ored = or True False;
-
 notted = not False;
+ranged = range 3 14;
+anyEven = any isEven list;
+allEven = all isEven list;
+flattened = flatten [[1, 2, 3], [4, 5, 6]];
+contains3 = contains 3 list;
+findEven = find isEven list;
 
 {
   filtered = filtered,
   summed = summed,
-  l = l,
+  listLen = listLen,
   reversed = reversed,
   take3 = take3,
   drop3 = drop3,
   zipped = zipped,
   anded = anded,
   ored = ored,
-  notted = notted
+  notted = notted,
+  ranged = ranged,
+  anyEven = anyEven,
+  allEven = allEven,
+  flattened = flattened,
+  contains3 = contains3,
+  findEven = findEven
 }