diff -r f483fe1813f0 -r 8d9239158d7a src/Doc/Isar_Ref/Inner_Syntax.thy
--- a/src/Doc/Isar_Ref/Inner_Syntax.thy	Tue Jun 26 10:49:37 2018 +0200
+++ b/src/Doc/Isar_Ref/Inner_Syntax.thy	Tue Jun 26 11:10:47 2018 +0200
@@ -391,7 +391,7 @@
     atom: @{syntax short_ident} | @{syntax int} | @{syntax float} | @{syntax cartouche}
   \<close>}
 
-  Each @{syntax entry} is a name-value pair: if the value is omitted, if
+  Each @{syntax entry} is a name-value pair: if the value is omitted, it
   defaults to \<^verbatim>\<open>true\<close> (intended for Boolean properties). The following
   standard block properties are supported: