Typo fixed.
--- a/doc-src/IsarImplementation/Integration.thy Tue Aug 28 15:07:43 2012 +0200
+++ b/doc-src/IsarImplementation/Integration.thy Tue Aug 28 16:33:06 2012 +0200
@@ -6,7 +6,7 @@
section {* Isar toplevel \label{sec:isar-toplevel} *}
-text {* The Isar toplevel may be considered the centeral hub of the
+text {* The Isar toplevel may be considered the central hub of the
Isabelle/Isar system, where all key components and sub-systems are
integrated into a single read-eval-print loop of Isar commands,
which also incorporates the underlying ML compiler.