diff -r 940530087f30 -r 6342d0570502 thys/Paper/Paper.thy
--- a/thys/Paper/Paper.thy	Tue Apr 05 09:27:36 2016 +0100
+++ b/thys/Paper/Paper.thy	Tue Apr 05 14:00:55 2016 +0100
@@ -803,7 +803,7 @@
 
   Derivatives as calculated by \Brz's method are usually more complex
   regular expressions than the initial one; the result is that the
-  deivative-based matching and lexing algorithms are often abysmally slow.
+  derivative-based matching and lexing algorithms are often abysmally slow.
   However, various optimisations are possible, such as the simplifications
   of @{term "ALT ZERO r"}, @{term "ALT r ZERO"}, @{term "SEQ ONE r"} and
   @{term "SEQ r ONE"} to @{term r}. These simplifications can speed up the