diff -r 50d3059de9c6 -r 6e2479089226 ProgTutorial/First_Steps.thy
--- a/ProgTutorial/First_Steps.thy	Tue May 14 13:39:31 2019 +0200
+++ b/ProgTutorial/First_Steps.thy	Tue May 14 16:59:53 2019 +0200
@@ -572,7 +572,7 @@
         |-> (fn x => fn y => x + y)*}
 
 text {* 
-  The combinator @{ML_ind ||>> in Basics} plays a central rôle whenever your
+  The combinator @{ML_ind ||>> in Basics} plays a central role whenever your
   task is to update a theory and the update also produces a side-result (for
   example a theorem). Functions for such tasks return a pair whose second
   component is the theory and the fist component is the side-result. Using