Fixup: NB GB 79 (C++20 CD): Add example for private-module-fragment

Author: Dawn Perchik

source/basic.tex

@@ -2607,8 +2607,9 @@
 of a sequence of declarations.
 
 \begin{bnf}
-\nontermdef{private-module-fragment}\br
-    \keyword{module} \terminal{:} \keyword{private} \terminal{;} \opt{top-level-declaration-seq}
+\nontermdef{translation-unit}\br
+    \opt{top-level-declaration-seq}\br
+    \opt{global-module-fragment} module-declaration \opt{top-level-declaration-seq} \opt{private-module-fragment}
 \end{bnf}
 
 \begin{bnf}

source/modules.tex

@@ -761,9 +761,8 @@
 \rSec1[module.private.frag]{Private module fragment}
 
 \begin{bnf}
-\nontermdef{translation-unit}\br
-    \opt{top-level-declaration-seq}\br
-    \opt{global-module-fragment} module-declaration \opt{top-level-declaration-seq} \opt{private-module-fragment}
+\nontermdef{private-module-fragment}\br
+    \keyword{module} \terminal{:} \keyword{private} \terminal{;} \opt{top-level-declaration-seq}
 \end{bnf}
 
 \pnum