diff --git a/lecture/lec01/lec01-live.ml b/lecture/lec01/lec01-live.ml
new file mode 100644
index 0000000000000000000000000000000000000000..daafe903a94183f9dd77eb62037e893c13e85862
--- /dev/null
+++ b/lecture/lec01/lec01-live.ml
@@ -0,0 +1,62 @@
+(* this is a comment 
+    (* they can even nest *)   
+*)
+
+#utop_prompt_dummy
+let _ = UTop.set_show_box false
+
+(* static environment: empty-ish 
+   dynamic enivornment: empty-ish   
+*)
+
+(* let variable-name = expression *)
+
+let x = 34
+
+(*
+  static environment: x : int  
+  dynamic enviornment: x = 34
+*)
+
+let y = 17
+
+(*
+  static environment: x : int, y : int
+  dynamic enviornment: x = 34, y = 17
+*)
+
+(* 
+              +
+            /   \
+           +     +
+          / \   / \
+          x  y  y 2
+
+*)
+
+
+
+let z = (x + y) + (y + 2)
+
+(*
+  static environment: x : int, y : int, z : int
+  dynamic enviornment: x = 34, y = 17, z = 70
+*)
+
+let q = z + 1
+
+let abs_of_z =
+  if z < 0 then
+    -z
+  else
+    z
+
+
+
+
+
+
+
+
+
+