more bnf_decl -> bnf_axiomatization

--- a/src/Doc/Datatypes/Datatypes.thy	Tue May 13 11:10:23 2014 +0200
+++ b/src/Doc/Datatypes/Datatypes.thy	Tue May 13 11:11:51 2014 +0200
@@ -2528,8 +2528,8 @@
 *}
 
 
-subsubsection {* \keyw{bnf\_decl}
-  \label{sssec:bnf-decl} *}
+subsubsection {* \keyw{bnf\_axiomatization}
+  \label{sssec:bnf-axiomatization} *}
 
 text {*
 \begin{matharray}{rcl}