diff --git a/abnf/hello-abnf/project.clj b/abnf/hello-abnf/project.clj
index 316277c..b528125 100644
--- a/abnf/hello-abnf/project.clj
+++ b/abnf/hello-abnf/project.clj
@@ -3,5 +3,6 @@
   :url "http://example.com/FIXME"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
             :url "https://www.eclipse.org/legal/epl-2.0/"}
-  :dependencies [[org.clojure/clojure "1.10.0"]]
+  :dependencies [[org.clojure/clojure "1.10.0"]
+                 [instaparse "1.4.10"]]
   :repl-options {:init-ns hello-abnf.core})
diff --git a/abnf/hello-abnf/src/hello_abnf/core.clj b/abnf/hello-abnf/src/hello_abnf/core.clj
index 533db80..ad32ed9 100644
--- a/abnf/hello-abnf/src/hello_abnf/core.clj
+++ b/abnf/hello-abnf/src/hello_abnf/core.clj
@@ -1,6 +1,16 @@
-(ns hello-abnf.core)
+(ns hello-abnf.core
+  (:require [instaparse.core :as insta]))
 
 (defn foo
   "I don't do a whole lot."
   [x]
   (println x "Hello, World!"))
+
+(def as-and-bs
+  (insta/parser
+   "S = AB*
+     AB = A B
+     A = 'a'+
+     B = 'b'+"))
+
+(as-and-bs "aaaaabbbaaaabb")