diff -r 4b47d8aaf5af -r 5eebea8f359f doc-src/TutorialI/Sets/sets.tex
--- a/doc-src/TutorialI/Sets/sets.tex	Thu Jan 25 11:59:52 2001 +0100
+++ b/doc-src/TutorialI/Sets/sets.tex	Thu Jan 25 15:31:31 2001 +0100
@@ -871,7 +871,7 @@
 Many familiar induction principles are instances of this rule. 
 For example, the predecessor relation on the natural numbers 
 is well-founded; induction over it is mathematical induction. 
-The `tail of' relation on lists is well-founded; induction over 
+The ``tail of'' relation on lists is well-founded; induction over 
 it is structural induction. 
 
 Well-foundedness can be difficult to show. The various