--- a/src/FOLP/ex/Intro.thy Wed Jan 12 15:53:37 2011 +0100
+++ b/src/FOLP/ex/Intro.thy Wed Jan 12 16:33:04 2011 +0100
@@ -76,7 +76,7 @@
shows "?p : ~ P"
apply (unfold not_def)
apply (rule impI)
-apply (rule prems)
+apply (rule assms)
apply assumption
done