doc-src/TutorialI/Misc/prime_def.thy
changeset 11456 7eb63f63e6c6
parent 9844 8016321c7de1
child 11457 279da0358aa9
--- a/doc-src/TutorialI/Misc/prime_def.thy	Wed Jul 25 18:21:01 2001 +0200
+++ b/doc-src/TutorialI/Misc/prime_def.thy	Thu Jul 26 16:43:02 2001 +0200
@@ -5,12 +5,12 @@
 text{*
 \begin{warn}
 A common mistake when writing definitions is to introduce extra free
-variables on the right-hand side as in the following fictitious definition:
+variables on the right-hand side.  Consider the following, flawed definition
+(where @{text"dvd"} means ``divides''):
 @{term[display,quotes]"prime(p) == 1 < p & (m dvd p --> (m=1 | m=p))"}
-where @{text"dvd"} means ``divides''.
 Isabelle rejects this ``definition'' because of the extra @{term"m"} on the
-right-hand side, which would introduce an inconsistency (why?). What you
-should have written is
+right-hand side, which would introduce an inconsistency (why?). 
+The correct version is
 @{term[display,quotes]"prime(p) == 1 < p & (!m. m dvd p --> (m=1 | m=p))"}
 \end{warn}
 *}