diff --git a/src/plfa/part1/Relations.lagda.md b/src/plfa/part1/Relations.lagda.md
index 2d6b7591..9028fa51 100644
--- a/src/plfa/part1/Relations.lagda.md
+++ b/src/plfa/part1/Relations.lagda.md
@@ -773,7 +773,7 @@ if it consists of a single zero (representing zero).
 
 Show that increment preserves canonical bitstrings:
 
-    Can x
+    Can b
     ------------
     Can (inc b)