/<nav>/,/<\/nav>/{/<a href/d}
/<nav>/a\
<a href="http://mupdf.com/index.html">About</a>\
<a href="http://mupdf.com/news.html">News</a>\
<a href="index.html">Documentation</a>\
<a href="http://mupdf.com/downloads/">Downloads</a>\
<a href="http://git.ghostscript.com/?p=mupdf.git;a=summary">Source</a>\
<a href="https://bugs.ghostscript.com/">Bugs</a>
