diff -r ade64af4c57c -r bb9dfcc87951 doc-src/TutorialI/Inductive/AB.thy
--- a/doc-src/TutorialI/Inductive/AB.thy	Fri Nov 24 16:49:27 2000 +0100
+++ b/doc-src/TutorialI/Inductive/AB.thy	Sun Nov 26 10:48:38 2000 +0100
@@ -303,6 +303,6 @@
 similar to the other cases (which are automatic in Isabelle). We conclude
 that the authors are at least cavalier about this point and may even have
 overlooked the slight difficulty lurking in the omitted cases. This is not
-atypical for pencil-and-paper proofs, once analysed in detail.  *}
+atypical for pen-and-paper proofs, once analysed in detail.  *}
 
 (*<*)end(*>*)