--- a/ProgTutorial/FirstSteps.thy	Sun Dec 06 14:26:14 2009 +0100
+++ b/ProgTutorial/FirstSteps.thy	Fri Jan 01 00:19:11 2010 +0100
@@ -406,10 +406,10 @@
 section {* Combinators\label{sec:combinators} *}
 
 text {*
-  For beginners perhaps the most puzzling parts in the existing code of Isabelle are
-  the combinators. At first they seem to greatly obstruct the
-  comprehension of the code, but after getting familiar with them, they
-  actually ease the understanding and also the programming.
+  For beginners perhaps the most puzzling parts in the existing code of
+  Isabelle are the combinators. At first they seem to greatly obstruct the
+  comprehension of code, but after getting familiar with them and handled with
+  care, they actually ease the understanding and also the programming.
 
   The simplest combinator is @{ML_ind I in Library}, which is just the 
   identity function defined as