-< source/img/graphical-toc.svg \
- perl -pe 's/(xlink:href="http)/target="_top" $1/' \
- | perl -pe 's/(xlink:href=".*?.html)/target="_top" $1/' \
- > build/html/graphical-toc.svg
+perl -pe 's/(xlink:href="(?:http|.*\.html))/target="_top" $1/' \
+ source/img/graphical-toc.svg > build/html/graphical-toc.svg