diff --git a/docs/design/iowo-design.typ b/docs/design/iowo-design.typ
index 76b4697..ce8f5c5 100644
--- a/docs/design/iowo-design.typ
+++ b/docs/design/iowo-design.typ
@@ -31,8 +31,6 @@
 #let terms = (
   "source",
   "ast",
-  "abstract syntax tree",
-  "Abstract Syntax Tree",
   "graph IR",
   "runtime",
 
@@ -193,12 +191,12 @@ Done with any of `--` or `//`.
 - Outputs of streamers are spliced into the contained list.
   - In effect, they are automatically flattened.
 
-== Abstract Syntax Tree
-
-Essentially just the source lexed and parsed.
-
 == Graph IR
 
+The parsed representation of the source, and also what the runtime operates on.
+
+In a way, this is the AST, except that it's not a tree.
+
 === Optimizer
 
 Merges and simplifies commands in the graph IR.