diff --git a/code/compiler/03/bad1.txt b/code/compiler/03/bad1.txt
new file mode 100644
index 0000000..86d4bc4
--- /dev/null
+++ b/code/compiler/03/bad1.txt
@@ -0,0 +1,2 @@
+data Bool = { True, False }
+defn main = { 3 + True }
diff --git a/code/compiler/03/bad2.txt b/code/compiler/03/bad2.txt
new file mode 100644
index 0000000..def8785
--- /dev/null
+++ b/code/compiler/03/bad2.txt
@@ -0,0 +1 @@
+defn main = { 1 2 3 4 5 }
diff --git a/code/compiler/03/works1.txt b/code/compiler/03/works1.txt
new file mode 100644
index 0000000..bedb5d8
--- /dev/null
+++ b/code/compiler/03/works1.txt
@@ -0,0 +1,2 @@
+defn main = { plus 320 6 }
+defn plus x y = { x + y }
diff --git a/code/compiler/03/works2.txt b/code/compiler/03/works2.txt
new file mode 100644
index 0000000..8332fde
--- /dev/null
+++ b/code/compiler/03/works2.txt
@@ -0,0 +1,3 @@
+defn add x y = { x + y }
+defn double x = { add x x }
+defn main = { double 163 }
diff --git a/code/compiler/03/works3.txt b/code/compiler/03/works3.txt
new file mode 100644
index 0000000..cfffd20
--- /dev/null
+++ b/code/compiler/03/works3.txt
@@ -0,0 +1,7 @@
+data List = { Nil, Cons Int List }
+defn length l = {
+    case l of {
+        Nil -> { 0 }
+        Cons x xs -> { 1 + length xs }
+    }
+}